APA

American Petroleum Institute A., . (1987). Guidelines for work in inert confined spaces in the petroleum industry. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 1987. Guidelines for work in inert confined spaces in the petroleum industry. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (1987). Guidelines for work in inert confined spaces in the petroleum industry. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . Guidelines for work in inert confined spaces in the petroleum industry. Washington: American Petroleum Institute, API. 1987.