APA (7th ed.) Citation

O-HARA, A. A practical guide to gas contracting. Penn Well.

Chicago Style (17th ed.) Citation

O-HARA, Ann. A Practical Guide to Gas Contracting. Penn Well.

MLA (8th ed.) Citation

O-HARA, Ann. A Practical Guide to Gas Contracting. Penn Well.

Warning: These citations may not always be 100% accurate.