Gaya APA
MACCOLLUM, D, , V. (2007).
Contruction safety Engineering Principles Desicning and Managing Safer Job Sites .
Singapore:
Mc Graw Hill.
Gaya MLA
MACCOLLUM, David, , V.
"Contruction safety Engineering Principles Desicning and Managing Safer Job Sites".
Singapore:
Mc Graw Hill,
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BUKU.