Weaver, Robert D. An integrated model of perennial and annual crop production for Sub-Saharan countries / Robert D. Weaver. - [Washington, D.C. : World Bank (WB) , 1989 - 60p. ; 28 cm. - Policy, planning, and research working papers ; WPS 175 . Includes bibliographical references. Subjects--Topical Terms: Agriculture--Economic aspects--Econometric models--Africa, Sub-SaharanFood crops--Economic aspects--Econometric models--Africa, Sub-SaharanFarms, Small--Econometric models--Africa, Sub-Saharan Gov. Doc. Class. No.: UN WB IED WP-175