Benjamin, N. C., Mbaye, A. A., & Diop, I. T. (2012). The informal sector in Francophone Africa: Firm size, productivity and institutions. World Bank.

Benjamin, Nancy C., Ahmadou Aly Mbaye, and Ibrahima Thione Diop. The Informal Sector in Francophone Africa: Firm Size, Productivity and Institutions. Washington, D.C.: World Bank, 2012.

Benjamin, Nancy C., et al. The Informal Sector in Francophone Africa: Firm Size, Productivity and Institutions. World Bank, 2012.