British Standards Institution. Specification for engineers' parallels (1st revision.). B.S.I.
Dyfyniad Arddull ChicagoBritish Standards Institution. Specification for Engineers' Parallels. 1st revision. London: B.S.I.
Dyfyniad MLABritish Standards Institution. Specification for Engineers' Parallels. 1st revision. B.S.I.
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