Seeburg, P. H., Lee, W. H., Nunn, M. F., & Duesberg, P. H. (1984). The 5' ends of the transforming gene of Fujinami sarcoma virus and of the cellular proto-fps gene are not colinear. Virology, 133(2), 460-464. doi:10.1016/0042-6822(84)90414-8.