APA

American Petroleum Institute A., . (2007). Contractor safety management for oil gas drilling and production operations. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 2007. Contractor safety management for oil gas drilling and production operations. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (2007). Contractor safety management for oil gas drilling and production operations. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . Contractor safety management for oil gas drilling and production operations. Washington: American Petroleum Institute, API. 2007.