APA
American Petroleum Institute A., . (2008). Use of 9Cr-1Mo-V (grade91) steel in the oil refining industry. Washington: American Petroleum Institute, API.
Chicago
American Petroleum Institute API, . 2008. Use of 9Cr-1Mo-V (grade91) steel in the oil refining industry. Washington: American Petroleum Institute, API.
Harvard
American Petroleum Institute A., . (2008). Use of 9Cr-1Mo-V (grade91) steel in the oil refining industry. Washington: American Petroleum Institute, API.
MLA
American Petroleum Institute API, . Use of 9Cr-1Mo-V (grade91) steel in the oil refining industry. Washington: American Petroleum Institute, API. 2008.