[1] L. BICAN P. JAMBOR T. KEPKA P. NĚMEC: 
Preradicals. Comment. Math. Univ. Carolinae 15 (1974), 75-83. 
MR 0347906[2] L. BICAN P. JAMBOR T. KEPKA P. NĚMEC: 
Hereditary and cohereditary preradicals. (to appear). 
MR 0414611[3] L. BICAN P. JAMBOR T. KEPKA P. NĚMEC: 
Stable and costable preradicals. (to appear). 
MR 0387333[4] L. BICAN P. JAMBOR T. KEPKA P. NĚMEC: 
Composition of preradicals. (to appear). 
MR 0357468[5] R. S. CUNNINGHAM E. A. RUTTER, Jr. D. R. TURNIDGE: 
Rings of quotients of endomorphism rings of projective modules. Pac. Jour. Math. (3) 41 (1972), 647-667. 
MR 0318200