APA
McCormick J., United Nations Environment Programme, . (1991). Urban air pollution. Nairobi: UNEP.
Chicago
McCormick John, United Nations Environment Programme, . 1991. Urban air pollution. Nairobi: UNEP.
Harvard
McCormick J., United Nations Environment Programme, . (1991). Urban air pollution. Nairobi: UNEP.
MLA
McCormick John, United Nations Environment Programme, . Urban air pollution. Nairobi: UNEP. 1991.