References
- Abbiw D.K. (1990): Useful plants of Ghana: West African uses of wild and cultivated plants. Kew: intermediate Technology Publications and the Royal Botanic Gardens, pp. 328
- Akinpelu A.O., Amamgbo L.E.F., Nwauwa L.O.E., Adenegan K.O. (2012): Sweet Potato Marketing: Agricultural Productivity and Growth in Abia State, Nigeria. In Nwaru, Mejeha, Okoye, Nwachukwu, Ekumankama, Agugo, Iheke and Ogbe (Eds): Agricultural Productivity and Growth: Strategies for meeting the MDGs, Proceedings of the 26th Annual Conference of Farm Management Association of Nigeria, pp. 109-114.
- Enete A.A., Agbugba I.K. (2008): Charcoal Marketing in Abia State, in Ume, Obinne and Lawal (Eds): Prospects and Challenges of Adding Value to Agricultural Products; Proceedings of the 22nd Annual Conference of Farm Management Association of Nigeria, pp. 338-346.
- Falconer J. (1990): The Major Significance of “Minor” Forest Products: the Local and Value of Forests in West African Humid Forest Zone, Community Forestry Note No. 6. Rome, FAO.
- Goossens K. (1996): Cassava Production and Marketing in Zaire, Leuven University Press, Leuven, Belgium Granger C.W.J. (1969): Investigating Causal Relations by Econometric Method and Gross-spectral Methods, Econometrica 34: 424-438.
- Guwheya G.E., Mabaya I.U., Christy R.D (1998): Horticultural Marketing in Zimbabwe: Margins Price Transmission and Spatial Market Integration. Paper presented at the 57th European Association of Agricultural Economists Seminar, Wageningen, The Netherlands, 23-26 September 1998.
- Harrison K., Henley D., Riley H., Shaffer J. (1987): Improving Food Marketing Systems in Developing Countries: Experiences from Latin America, Department of Agricultural Economics, Michigan State University, East Lansing
- Michigan Hayami .Y.M., Kikuchi H., Marcino E.B. (1999): Middlemen and Peasants in Rice Marketing in the Philippines. Agricultural Economic 20: 79-93.
- Houck J.P. (1977): An Approach to Specifying and Estimating Non-reversible Functions, American Journal of Agricultural Economics, 59 (2), 570-572.
- Iheanacho A.C. (2005): Structural Characteristics and Performance of Retail Marketing of Eggs in Maiduguri Metropolis of Borno State, Nigeria, Journal of Sustainable Development in Agriculture and Environment Online Issues 2: 24-31.
- Ike P.C. (2008): Estimating Production Technical Efficiency in Irvingia Seed (Ogbono) Species Farmers in Nsukka Agricultural Zone in Enugu State, Nigeria, Journal of Sustainable Tropical Agricultural Research 28: 1-7.
- International Centre for Research in Agro-forestry 1995, ICRAF Annual Report 1994, Nairobi Kenya, 239 p.
- Ladipo D.O., Boland D.J. (1994): Trade in Irvingia Kernels: In D.C. Ladipo and D.J. Boland (Eds): Proceedings of the International Workshop on Irvingia in West Africa. International Centre for Research in Agro-forestry (ICRAF), Nairobi, Kenya, 291 p.
- Leakey R.R.B., Schreckenberg K., Tchoundjeu Z. (2003): The Participatory Domestication of Indigenous Fruits, International Forestry Review 5: 338-347.
- Riley H. (1972): Improving Internal Marketing Systems as part of National Development systems, Occasional paper No. 3, Michigan State University, Latin American Studies Center, East Lansing.
- Tomek W.G., Robinson K.I. (1990): Agricultural Product Prices, 3rd Ed., New York, USA, Cornell University.
- United Nations Development Programme UNDP (1992): The Importance of Forestry Statistics, Retrieved at http:// www.pon-lin.com/CFA/doi/10.1505/ifor.8.1.4
- World Resource Institute (2005): Environmental Income by Ecosystem. Retrieved at http://www.multimedia.wri.org. wr2005/index.html-14k