Social Welfare, 374.80297, 910.202, Dewey: 374.80297, Dewey: 910.202, Travel Guidebooks., Vacations Guidebooks., Voluntarism., Estudio y enseñanza
363.738/7403, Climatic changes Encyclopedias., Climatic changes. (OCoLC)fst00864229, Dewey: 363.738/7403, Encyclopedias. (OCoLC)fst01423798, Global warming Encyclopedias., Global warming. (OCoLC)fst00943506, TECHNOLOGY & ENGINEERING Environmental Pollution Control., Estudio y enseñanza, Electronic books