Spellman, F. R. (1997). Wastewater biosolids to compost. Technomic.
Cita Chicago (17th ed.)Spellman, Frank R. Wastewater Biosolids to Compost. Lancaster: Technomic, 1997.
Cita MLA (9th ed.)Spellman, Frank R. Wastewater Biosolids to Compost. Technomic, 1997.
Atenció: Aquestes cites poden no estar 100% correctes.