Institution, 8. B. S. (1990). Cross recesses for screws. London : British Standards Institution.
Cita Chicago (17th ed.)Institution, 8096 British Standards. Cross Recesses for Screws. London : British Standards Institution, 1990.
Cita MLA (9th ed.)Institution, 8096 British Standards. Cross Recesses for Screws. London : British Standards Institution, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.