Conkin, P. (2007). The state of the earth: Environmental challenges on the road to 2100. Universities Press.
Chicago-viite (17. p.)Conkin, Paul. The State of the Earth: Environmental Challenges on the Road to 2100. Hyderabad: Universities Press, 2007.
MLA-viite (9. p.)Conkin, Paul. The State of the Earth: Environmental Challenges on the Road to 2100. Universities Press, 2007.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.