1. Soil Failure by Introducing Air under Pressure;Araya K.;Transactions of the ASAE,1984
2. The Working Performance of Animal-drawn Implements for Soil Tillage in Western Africa;Betker J. R.;Agricultural Engineering,1989
3. Characteristics of a Teflon-covered Simple Tool;Fox W. R.;Transactions of the ASAE,1969
4. The Mechanics of Animal-draught Cultivation Implements;Inns F. M.;The Agricultural Engineer,1990