NCSC-TG-003: A Guide to Understanding Discretionary Access Control in Trusted Systems, 30 September 1987. (Neon Orange Book)
You can download it from the following link: https://packetstormsecurity.com/files/download/13994/NCSC-TG-003.txt
Source: https://packetstormsecurity.com/files/13994/NCSC-TG-003.txt.html