- GROWING DEGREE DAYS http://www.gddtracker.net/
- TURF CALCULATOR http://aggie-turf.tamu.edu/answers4you/turfcalculators.htm
- TURF DISEASES http://www.msuturfdiseases.net/
- SPORT TURF INFORMATION http://www.stma.org/knowledge-center
- MICHIGAN TURFGRASS FOUNDATION http://www.michiganturfgrass.org
- MI GOLF COURSE SUPT. ASSOCIATION http://www.migcsa.org/
- OHIO STATE UNIVERSITY TURFGRASS http://buckeyeturf.osu.edu/
- PURDUE TURF PATHOLOGY https://ag.purdue.edu/btny/Extension/pages/turfpathology.aspx
- CORNELL TURFGRASS http://www.hort.cornell.edu/turf/
- TURFNET http://www.turfnet.com