APA

British Standard. BS 505:1971, . (1976). Road traffic signals. London: British Standard. BS 505:1971.

Chicago

British Standard. BS 505:1971, . 1976. Road traffic signals. London: British Standard. BS 505:1971.

Harvard

British Standard. BS 505:1971, . (1976). Road traffic signals. London: British Standard. BS 505:1971.

MLA

British Standard. BS 505:1971, . Road traffic signals. London: British Standard. BS 505:1971. 1976.