An empirical comparison of pie vs. linear menus. - John R. Callahan; Don Hopkins; Mark D. Weiser; Ben Shneiderman (CHI, 1988)

Parse Tree Annotations. - James M. Purtilo; John R. Callahan (Commun. ACM, 1989)

A Packaging System For Heterogeneous Execution Environments. - John R. Callahan; James M. Purtilo (IEEE Trans. Software Eng., 1991)

Functional specifications for collaboration services. - George Almási 001; Aliasghar Babadi; W. Brandt; A. Butcher; John R. Callahan; K. J. Cleetus; M. E. Fotta; C. Gollapudy; N. Gradetsky; S. Iyer; Vasudevan Jagannathan; Raghu Karinthi; et al. (WETICE, 1994)

A decentralized software bus based on IP multicasting. - John R. Callahan; Todd L. Montgomery (WETICE, 1994)

Using Technology to Enable Collaboration: WET ICE '95. - John R. Callahan (IEEE Expert, 1995)

An Approach to Verification and Validation of a Reliable Multicasting Protocol. - John R. Callahan; Todd L. Montgomery (ISSTA, 1996)

Independent validation of specifications: a coordination headache. - Steve M. Easterbrook; John R. Callahan (WETICE, 1996)

Formal Methods for V&V of Partial Specifications: An Experience RSeport. - Steve M. Easterbrook; John R. Callahan (RE, 1997)

Validating Requirements for Fault Tolerant Systems using Model Checking. - Francis Schneider; Steve M. Easterbrook; John R. Callahan; Gerard J. Holzmann (ICRE, 1998)

V & V through Inconsistency Tracking and Analysis. - Steve Easterbrook; John R. Callahan; Virginie Wiels (IWSSD, 1998)

Web-Based Issue Tracking for Large Software-Projects. - John R. Callahan; Reshma R. Khatsuriya; Randy Hefner (IEEE Internet Comput., 1998)

Formal methods for verification and validation of partial specifications: A case study. - Steve M. Easterbrook; John R. Callahan (J. Syst. Softw., 1998)

The Future of Identity. - John R. Callahan (IT Prof., 2019)