NCSC-TG-013 Ver.2: RAMP Program Document, 1 March 1995, Version 2 (Pink Book)
You can download it from the following link: https://packetstormsecurity.com/files/download/14003/NCSC-TG-013.2.txt
Source: https://packetstormsecurity.com/files/14003/NCSC-TG-013.2.txt.html