WHO OFFSET PUBL. ; NR 76 296,036 AIR Air quality in selected urban areas 1979— 1980 : / GEMS : Global Environmental Minitoring System 1 / prep, in cooperation with the W H O Collaborating Centre on Environmental Pollution Control, United States Environmental Protection Agency, Washington, DC, USA . — Geneva : World Health Organization, 1983. — 57 s. : il. ; 30 cm (WHO Offset Publ.; nr 76) ISBN 92 4 1700769