APA

American Petroleum Institute A., . (1990). Digest of state boiler and pressure vessel rules and regulations. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 1990. Digest of state boiler and pressure vessel rules and regulations. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (1990). Digest of state boiler and pressure vessel rules and regulations. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . Digest of state boiler and pressure vessel rules and regulations. Washington: American Petroleum Institute, API. 1990.