APA (7th ed.) Citation

Chilton, P. A. (1989). Introducing X.400. NCC Publications.

Chicago Style (17th ed.) Citation

Chilton, Paul A. Introducing X.400. Manchester: NCC Publications, 1989.

MLA (8th ed.) Citation

Chilton, Paul A. Introducing X.400. NCC Publications, 1989.

Warning: These citations may not always be 100% accurate.