Token-passing bus access method and physical layer specifications : IEEE standards for local area networks / sponsor, Technical Committee on Computer Communications of the IEEE Computer Society
Spine title: 802.4 token-passing bus. At head of title: An American national standard. "Approved June 13, 1984, IEEE Standards Board; approved December 17, 1984, American National Standards Institute." ANSI/IEEE Std 802.4-1985; ISO draft international standard 8802/4."