The most comprehensive and recent discussion of NL-Soar can be found in:

A Building Block Approach to a Unified Language Capability. (1997) Lehman, J., VanDyke, J. Lonsdale, D., Green, N., and Smith, M. Journal of Artificial Intelligence Research. (submitted).

also

Sentence processing with limited resources: A Soar-based architectural theory. (1997). Lewis, R.L., and Lehman, J. F. Psychological Review. (submitted).

Applications of the more recent versions of NL-Soar are discussed in the following:

Compiling knowledge for dialogue generation and interpretation. (1996). Green, N., and Lehman, J.F. Tech rep CMU-CS-96-175, School of Computer Science, Carnegie Mellon University.

An Architecturally-based Theory of Human Sentence Comprehension. (1993). Richard. L. Lewis Ph.D. thesis, Carnegie Mellon University.

Natural language processing for IFORs: comprehension and generation in the air combat domain. (1995). Lehman, J., VanDyke, J., and Rubinoff, R. In Proceedings of the Fifth Conference on Computer Generated Forces and Behavioral Representation

Modeling SI: A cognitive approach. (1997). Lonsdale, D. Interpreting: International Journal of Research and Practice in Interpreting, 1(2). Integrating cognitive capabilities in a real-time task. (1994). Nelson, G., Lehman, J.F., and John, B.E. In Proceedings of the Sixteenth Annual Conference of the Cognitive Science Society.

Experiences in interruptible language processing. (1994) Nelson, G., Lehman, J.F., and John, B.E.

An architectural account of errors in foreign language learning. (1997) Van Dyke, J. and Lehman, J. In Proceedings of the Nineteenth Annual Conference of the Cognitive Science Society.

Discussions of earlier versions of NL-Soar are available here:

Natural Language Comprehension in Soar: Spring 1991. (1991). Lehman, J.F., Lewis, R., and Newell, A. Tech. Report, School of Computer Science, Carnegie Mellon University, CMU-CS-91-117.

Other related articles:

The role of language in cognition. (1993). Lehman, J.F., Newell, A.N., Polk, T., and Lewis, R.L. In Conceptions of the Human Mind . Lawrence Erlbaum Associates, Inc.

Meaning matters: Response to Miller. (1996) Lehman, J.F. In Steier, D.M. and Mitchell, T.M. (Eds.), Mind Matters: A Tribute to Allen Newell. Lawrence Erlbaum Associates.

Interference in short-term memory: The magical number two (or three) in sentence processing. (1996). Lewis. R.L. Journal of Psycholinguistic Research, 25, 93-115.