@INPROCEEDINGS {VOGEL:1989,
title = {Economic returns of alley farming},
author = {Vogel, W. O. and Mutsaers, H. J. W. },
booktitle = {Alley farming in the humid and subhumid tropics, proceedings edited by B.T. Kang; L. Reynolds},
year = {1989},
pages = {197--207},
publisher = {IDRC},
address = {Ottawa},
}