APA
Lengyel P. (., United Nations Educational S. a. C. O. (., . (1971). Approaches to the science of socio-economic development. Paris: UNESCO.
Chicago
Lengyel Peter (Ed.), United Nations Educational Scientific and Cultural Organisation (Paris), . 1971. Approaches to the science of socio-economic development. Paris: UNESCO.
Harvard
Lengyel P. (., United Nations Educational S. a. C. O. (., . (1971). Approaches to the science of socio-economic development. Paris: UNESCO.
MLA
Lengyel Peter (Ed.), United Nations Educational Scientific and Cultural Organisation (Paris), . Approaches to the science of socio-economic development. Paris: UNESCO. 1971.