Clement, S. (2007). Manual Procura+ (2a ed.). ICLEI, Local Governments for Sustainability : Procura+, Campanya de compra sostenible.
Cita Chicago (17th ed.)Clement, Simon. Manual Procura+. 2a ed. Barcelona: ICLEI, Local Governments for Sustainability : Procura+, Campanya de compra sostenible, 2007.
Cita MLA (9th ed.)Clement, Simon. Manual Procura+. 2a ed. ICLEI, Local Governments for Sustainability : Procura+, Campanya de compra sostenible, 2007.