Kohli, R.K. & Batish, D.R. & Singh, H.P.: Ecology – Population and Community Ecology, s. 2. Centre for Environment and Vocational Studies, Panjab University, 18.9.2007. Teoksen verkkoversio (viitattu 21.12.2019). (Arkistoitu – Internet Archive)
oxfordreference.com
Modular organismOxford Reference. Viitattu 21.12.2019. (englanniksi)
web.archive.org
Kohli, R.K. & Batish, D.R. & Singh, H.P.: Ecology – Population and Community Ecology, s. 2. Centre for Environment and Vocational Studies, Panjab University, 18.9.2007. Teoksen verkkoversio (viitattu 21.12.2019). (Arkistoitu – Internet Archive)