APA

American Petroleum Institute A., . (2015). Gate, globe, and check valves for sizes DN 100 (NPS 4) and smaller for the petroleum and natural gas industries. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 2015. Gate, globe, and check valves for sizes DN 100 (NPS 4) and smaller for the petroleum and natural gas industries. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (2015). Gate, globe, and check valves for sizes DN 100 (NPS 4) and smaller for the petroleum and natural gas industries. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . Gate, globe, and check valves for sizes DN 100 (NPS 4) and smaller for the petroleum and natural gas industries. Washington: American Petroleum Institute, API. 2015.