2016-06-16. ISBN 978-3-319-30750-3 (英语). Donald B. Freeman, City of Farmers: Informal Urban Agriculture in the Open Spaces of Nairobi, Kenya, McGill-Queen's
ISBN 9780195368369 Ana Rosa Chagas Cavalcanti (2018). Housing Shaped by Labour: The Architecture of Scarcity in Informal Settlements. (Berlin: Jovis Press). ISBN 9783868595345
Johns Hopkins University Press. 1974. ISBN 0-8018-1600-9. OCLC 897554. informal non-formal and formal education – a brief overview of some different approaches