Não informado. (2009). Gas International. Institution of Gas Engineers and Managers.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Gas International. Loughborough, Inglaterra: Institution of Gas Engineers and Managers, 2009.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Gas International. Institution of Gas Engineers and Managers, 2009.
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