O'HARA, A. (1999). A practical guide to gas contracting. Penn Well.
Chicago Style (17th ed.) CitationO'HARA, Ann. A Practical Guide to Gas Contracting. Penn Well, 1999.
MLA (8th ed.) CitationO'HARA, Ann. A Practical Guide to Gas Contracting. Penn Well, 1999.
Warning: These citations may not always be 100% accurate.