This is not a peer-reviewed article. L. Harms and W. Guse. 2000. Electrical/Hydraulic Proportional Control Valves and Their Use in Agriculture Powershift Transmissions. ASAE Distinguished Lecture No. 24, pp. 1-9. Agricultural Equipment Technology Conference, 23-25 February 2000, Kansas City, Missouri USA. Copyright 2000 American Society of Agricultural Engineers. ASAE Publication No. 913C0500.
