Cita APA (7a ed.)

B.S.I. (1957). Pipe threads . B.S.21. British Standards Institution.

Cita Chicago Style (17a ed.)

B.S.I. Pipe Threads . B.S.21. London: British Standards Institution, 1957.

Cita MLA (9a ed.)

B.S.I. Pipe Threads . B.S.21. British Standards Institution, 1957.