APA

American Petroleum Institute A., . (1994). API engine oil licensing and certification system: 1994 licensees. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 1994. API engine oil licensing and certification system: 1994 licensees. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (1994). API engine oil licensing and certification system: 1994 licensees. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . API engine oil licensing and certification system: 1994 licensees. Washington: American Petroleum Institute, API. 1994.