WSU Turf Program in Pullman, W.J. Johnston, Washington State University.
OSU Turf Management, Oregon State University, Department of Horticulture.
Clopyralid in compost. Craig Cogger and Andy Barry, Washington State University Puyallup. Close-up color plates of the damage on beans from clopyralid.
Golf Course Superintendents Association of America. The foremost national association for golf course superintendents and their staff.
Turfgrass Producers International. Rolling Meadows, Illinois.
Agricultural weed gallery from New Jersey. Rutgers University. Very nice color thumbnails of lawn weeds. Click to see larege images.