Different pseudotypes of Friend spleen focus-forming virus induce polycythemia and erythropoietin-independent colony formation in serum-free medium.
MacDonald ME, Johnson GR, Bernstein A. Different pseudotypes of Friend spleen focus-forming virus induce polycythemia and erythropoietin-independent colony formation in serum-free medium. Virology. 1981 Apr 15; 110(1):231-6.