https://digitalcommons.unl.edu/usdaarsfacpub/1945/
"Registration of WS4U and WS8U Switchgrass Germplasms" by M. D. Casler, Kenneth P. Vogel et al.
Two upland switchgrass (Panicum virgatum L.) germplasm pools, WS4U (Reg. no. GP-92, PI 639191) and WS8U (Reg. no. GP-93, PI 639192), were released...