Παραπομπή σε μορφή APA (7η εκδ.)

Gunaratne, L. (2010). Policy options for sustainable river sand mining in Sri Lanka. Economu and Environment Program for Southeast Asia.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Gunaratne, L.H.P. Policy Options for Sustainable River Sand Mining in Sri Lanka. Singapore: Economu and Environment Program for Southeast Asia, 2010.

Παραπομπή σε μορφή MLA (9th εκδ.)

Gunaratne, L.H.P. Policy Options for Sustainable River Sand Mining in Sri Lanka. Economu and Environment Program for Southeast Asia, 2010.