APA
American Petroleum Institute A., . (1988). Specification for drilling and well servicing structures. Washington: American Petroleum Institute, API.
Chicago
American Petroleum Institute API, . 1988. Specification for drilling and well servicing structures. Washington: American Petroleum Institute, API.
Harvard
American Petroleum Institute A., . (1988). Specification for drilling and well servicing structures. Washington: American Petroleum Institute, API.
MLA
American Petroleum Institute API, . Specification for drilling and well servicing structures. Washington: American Petroleum Institute, API. 1988.