APA

American Gas Association A., Operations Conference (2012 mayo 1-4 ; San Francisco C. U., . (2012). 2012 Operating section proceedings. San Francisco: American Gas Association, AGA.

Chicago

American Gas Association AGA, Operations Conference (2012 mayo 1-4 ; San Francisco California USA), . 2012. 2012 Operating section proceedings. San Francisco: American Gas Association, AGA.

Harvard

American Gas Association A., Operations Conference (2012 mayo 1-4 ; San Francisco C. U., . (2012). 2012 Operating section proceedings. San Francisco: American Gas Association, AGA.

MLA

American Gas Association AGA, Operations Conference (2012 mayo 1-4 ; San Francisco California USA), . 2012 Operating section proceedings. San Francisco: American Gas Association, AGA. 2012.