APA

American Petroleum Institute A., . (1997). Recommended practice for classification of locations for electrical installations at petroleum facilities classified as class I, zone 0, zone 1, and zone 2. Washington: American Petroleum Institute, API.

Chicago

American Petroleum Institute API, . 1997. Recommended practice for classification of locations for electrical installations at petroleum facilities classified as class I, zone 0, zone 1, and zone 2. Washington: American Petroleum Institute, API.

Harvard

American Petroleum Institute A., . (1997). Recommended practice for classification of locations for electrical installations at petroleum facilities classified as class I, zone 0, zone 1, and zone 2. Washington: American Petroleum Institute, API.

MLA

American Petroleum Institute API, . Recommended practice for classification of locations for electrical installations at petroleum facilities classified as class I, zone 0, zone 1, and zone 2. Washington: American Petroleum Institute, API. 1997.