APA
World Bank Reprint Seies no 120, . (1986). Engineering Economics of the Maintenance of Earth and Gravel Roads. World Bank: .
Chicago
World Bank Reprint Seies no 120, . 1986. Engineering Economics of the Maintenance of Earth and Gravel Roads. World Bank: .
Harvard
World Bank Reprint Seies no 120, . (1986). Engineering Economics of the Maintenance of Earth and Gravel Roads. World Bank: .
MLA
World Bank Reprint Seies no 120, . Engineering Economics of the Maintenance of Earth and Gravel Roads. World Bank: . 1986.