APA

Portes A., Castells M. & Benton L. A. (1989). The informal economy. London: Johns Hopkins University.

Chicago

Portes Alejandro, Castells Manuel and Benton Lauren A. 1989. The informal economy. London: Johns Hopkins University.

Harvard

Portes A., Castells M. and Benton L. A. (1989). The informal economy. London: Johns Hopkins University.

MLA

Portes Alejandro, Castells Manuel and Benton Lauren A. The informal economy. London: Johns Hopkins University. 1989.