Cita APA (7th ed.)
Spellman, F. R. Essentials of Environmental Engineering. Bernan.
Cita Chicago (17th ed.)
Spellman, Frank R. Essentials of Environmental Engineering. Lanham, EUA: Bernan.
Cita MLA (9th ed.)
Spellman, Frank R. Essentials of Environmental Engineering. Bernan.
Atenció: Aquestes cites poden no estar 100% correctes.