1. Kanas, N. A., & Fedderson, W. E. (1971). Behavioral, psychiatric, and sociological problems of long-duration space missions. NASA Technical Memorandum, NASA TM X-58067. National Aeronautics and Space Administration Manned Spacecraft Center. https://ntrs.nasa.gov/api/citations/19720008366/downloads/19720008366.pdf
2. Dunlap, R. D. (1966). Psychology and the crew on Mars missions. Paper presented at the AIAA/AAS Stepping Stones to Mars Meeting (pp. 441–445), Baltimore, MD, 28–30 Mar.
3. Wise Jr., H. G. (1966). Analysis of anticipated problems, effects of confinement of long duration manned space flights. Paper presented at NASA Symposium, Part 2, 17 Nov.
4. Bales, R. F., & Borgotta, E. F. (1966). Size of group as a factor in the interaction profile. In A. P. Hare, E. F. Borgotta, & R. F. Bales (Eds.), Small groups (Revised ed.). Knopf and Company.
5. Smith, W. M. (1966). Observations over the lifetime of a small isolated group. Psychological Reports, 19, 475–514.