APA
American Petroleum Institute A., . (2003). Marking liquid petroleum pipeline facilities. Washington: American Petroleum Institute, API.
Chicago
American Petroleum Institute API, . 2003. Marking liquid petroleum pipeline facilities. Washington: American Petroleum Institute, API.
Harvard
American Petroleum Institute A., . (2003). Marking liquid petroleum pipeline facilities. Washington: American Petroleum Institute, API.
MLA
American Petroleum Institute API, . Marking liquid petroleum pipeline facilities. Washington: American Petroleum Institute, API. 2003.