Polymorphism of the major envelope glycoprotein (gp70) of murine C-type viruses: virion associated and differentiation antigens encoded by a multi-gene family - Elder, J. H.; Jensen, F. C.; Bryant, M. L.; Lerner, R. A. (Nature Publishing Group, 1977)
http://dx.doi.org/10.1038/267023a0
Keywords: W; V; WW-YZ; TA-TD; U