@BOOK {DVORAK:1996a, title = {Labor requirement in assessment of technologies: IITA research guide, No. 27}, author = {Dvorak, K. A. }, series = {IITA research guide, No. 27}, year = {1996}, month = {October}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {14p.}, }