Pfeiffer, H.D.: The Effect of Data Structures Modifications on Algorithms for Reasoning Operations Using a Conceptual Graphs Knowledge Base. PhD Dissertation at New Mexico State University, December 2007.
Pfeiffer, H.D. and R.T. Hartley: A Comparison of Different Conceptual Structures Projection Algorithms, in U. Priss, S. Polovina, and R. Hill (eds), Conceptual Structures: Knowledge Architectures for Smart Applications, volume 4604 of LNAI, pages 165-178, ICCS, 2007.
Pfeiffer, H.D. and J.J. Pfeiffer, Jr.: Representation Levels Within Knowledge Representation (position paper), in U. Priss, S. Polovina, and R. Hill (eds), Conceptual Structures: Knowledge Architectures for Smart Applications, volume 4604 of LNAI, pages 484-487, ICCS, 2007.
Pfeiffer, H.D., N.R. Chavez, Jr. and J.J. Pfeiffer, Jr.: CPE Design Considering Interoperability In the 2nd Conceptual Structures Tool Interoperability Workshop, CS-TIW 2007, Sheffield Hallam University, Sheffield, UK, July 2007, pp 71-76.
Pfeiffer, H.D.: An Exportable CGIF Module from the CP Environment: A Pragmatic Approach, in Conceptual Structures at Work, 12th International Conference on Conceptual Structures, Proceedings of ICCS 2004, LNAI 3127, Huntsville, Alabama, USA, pp.319-332, 2004.
Hartley, R.T. and H.D. Pfeiffer: Data Models for Conceptual Structures, in Foundations and Applications of Conceptual Structures, Contributions to ICCS 2002, Borovets, Bulgaria 2002.
Pfeiffer, H.D. and R.T. Hartley: Visual CP Representation of Knowledge, in Supplimental Proceedings of the 8th International Conference On Conceptual Structures, ICCS 2000, Darmstadt, Germany 2000.
Pfeiffer, H.D. and B.J. Waltar: Automated Message Analysis Using the Conceptual Programming Environment, CP, in Supplimental Proceedings of the 3rd International Conference On Conceptual Structures, ICCS 1995, Santa Cruz, CA 1995.
Pfeiffer, H.D. and R.T. Hartley: Temporal, Spatial, and Constraint Handling in the Conceptual Programming Environment, CP, in Journal for Experimental and Theoretical AI 4:2, pp.167-182, 1992.
Pfeiffer, H.D. and R.T. Hartley: The Conceptual Programming Environment, CP: Reasoning Representation using Graph Structures and Operations, in Proc. of IEEE Workshop on Visual Languages, Kobe, Japan. 1991.
Pfeiffer, H.D. and R.T. Hartley: The Conceptual Programming Environment, CP: Time, Space and Heuristic Constraints, in Proc. of the Sixth Annual Workshop on Conceptual Graphs, Binghamton, NY. 1991.
Pfeiffer, H.D. and R.T. Hartley: Set Representation and Processing Additions to Conceptual Programming, in Proc. of the Fifth Annual Workshop on Conceptual Graphs, Boston, MA, A.15-1 - 10. 1990.
Pfeiffer, H.D, and Hartley, R.T. Semantic additions to Conceptual Programming, in Proc. 1989 Conceptual Graphs workshop, Detroit, MI, August 1989.
Pfeiffer, H.D. and R.T. Hartley: ARCEdit-CGEditor, in CGTools Workshop Proceedings in connection with ICCS2001, Stanford, CA. 2001.
Pfeiffer, H.D. and E.L. Tonkin: Evidence-based software engineering methods for development, analysis and evaluation of data structures, poster at SIG CR Workshop: "Bridging Worlds, Connecting People: Classification Transcending Boundaries", November 2009.
Pfeiffer, H.D. and E.L. Tonkin: eTagging in Context: Information Management across Community Networks, in Tatyana Dumova and Richard Fiordo (Ed.) Handbook of Research on Social Interaction Technologies and Collaboration Software: Concepts and Trends. IGI Global Press. pp. 158-169, July, 2009.
Tonkin, E. and H.D. Pfeiffer: A Case Study of Software-Assisted Collaborative Ontology Building, presentation at ICKM 2008.
Pfeiffer, H.D., E. Tonkin, M.R. Lindner, M.E.I. Kipp, and D.R. Millen: Tagging As A Communication Device: Every Tag Cloud has a Silver Lining, in People Transforming Information - Information Transforming People, 2008 Annual Meeting, ASIS&T'08, October 2008.
Zhang, Q., T. Krichel, C. Malone, H.D. Pfeiffer and S.L. Shreeves: Knowledge Sharing and Management in Open Access e-Resources & Communities, in press for 2008 Annual Meeting, ASIS&T'08, People Transforming Information - Information Transforming People, Columbus, OH, October 2008.
Tonkin, E., E.M. Corrado, H.L. Moulaison, M.E.I. Kipp, A. Resmini, H.D. Pfeiffer, and Q. Zhang: Collaborative and Social Tagging Networks. In Ariadne, Issue 54, January 2008.
Pfeiffer, H.D., Q. Zhang, E. Tonkin, E.M. Corrado, M.E.I. Kipp, and H.L. Moulaison: Tagging and Social Networks: The Impact of Communities on User Centered Tagging. Panel Presentation at 2007 Annual Meeting, ASIS&T'07, Joining Research and Practice: Social Computing and Information Science, Milwaukee, WI, October 2007.
Pfeiffer, H.D.: Games for Co-Evolution of Digital Resources and Knowledge Tools, Poster in Information Realities: Shaping the Digital Future for All, ASIS&T'06, Austin, TX. November 2006.
Keeler, M.A. and H.D. Pfeiffer: Building a Pragmatic Methodology for KR Tool Research and Development, in H. Scharfe, P. Hitzler, and P. Ohrstrom, editors, Conceptual Structures: Inspiration and Application, LNAI, Proceedings of ICCS 2006, Aalborg, Denmark, pp. 314-330 (2006).
Keeler, M.A. and H.D. Pfeiffer: Collaboratory testbed partnerships as a knowledge capture challenge, in P. Clark and G. Schreiber, editors, Proceedings of the Third International Conference on Knowledge Capture, pages 203-204, KCAP'05, ACM Press, October 2005.
Keeler, M.A. and H.D. Pfeiffer: Games of Inquiry for Collaborative Concept Structuring , in F. Dau, M-L Mugnier, and G. Stumme, editors, Conceptual Structures: Common Semantics for Sharing Knowledge, volume 3596 of LNAI, pages 396-410, ICCS2005, Springer, July 2005.
Pfeiffer, H.D.: Games of Inquiry for Collaborative Concept Structuring Presentation abstract from Graduate Research and Arts Symposium, Las Cruces, New Mexico, April 15, 2005.
Pfeiffer, H.D., Faculty Advisor - R.T. Hartley: The Effect Of Data Structures Modifications On Algorithms For Reasoning Operations, Doctoral Consortium Presentation in Richard Tapia Celebration of Diversity in Computing Conference, Albuquerque, NM. October 2005.
Pfeiffer, H.D., N.R. Chavez, Jr. and R.T. Hartley: A Generic Interface for Communication between Story Understanding Systems and Knowledge Bases , Poster Abstract in Richard Tapia Celebration of Diversity in Computing Conference, Albuquerque, NM. October 2005.
Hartley, R.T., H.D. Pfeiffer, and Dihong Qui: Representation for ViewGen: Structures and Reasoning, in Workshop on Propositional Knowledge Representation, Stanford, CA. 1992.
Coombs, M.J., H.D. Pfeiffer and R.T. Hartley: e-MGR: an Architecture for Symbolic Plasticity, in the special issue of International Journal of Man-Machine Studies on in Symbolic Problem Solving in Noisy, Novel, and Uncertain Task Environments, 36, pp.1-17, 1992.
Fields, C.A., Pfeiffer, H.D., Eskridge, T.C.: Knowledge representation and control in gm1, and automated DNA sequence analysis system based on the MGR architecture, in International Journal of Man-Machine Studies, 34, pp.549-573, 1991.
Coombs, M.J., Hartley, R.T., Pfeiffer, H.D., Kilgore, B.: How to become immune to facts. Proc. Rocky Mountain Conference on Artificial Intelligence, Las Cruces, June 1990.