Kraus, Richard S. Petroleum Refining Process in 78. Oil and Natural Gas, Kraus, Richard S., Editor, Encyclopedia of Occupational Health and Safety, Jeanne Mager Stellman, Editor-in-Chief. ILO, ジュネーヴ. &#copy; 2011. Petroleum Refining Process、オリジナルの2013年7月24日のアーカイブ
Kraus, Richard S. Petroleum Refining Process in 78. Oil and Natural Gas, Kraus, Richard S., Editor, Encyclopedia of Occupational Health and Safety, Jeanne Mager Stellman, Editor-in-Chief. ILO, ジュネーヴ. &#copy; 2011. Petroleum Refining Process、オリジナルの2013年7月24日のアーカイブ