QF-3 rings. Claus Michael Ringel, H. Tachikawa (1975) Journal für die reine und angewandte Mathematik
Quasitilted algebras have preprojective components Ole Enge (2000) Colloquium Mathematicae We show that a quasitilted algebra has a preprojective component. This is proved by giving an algorithmic criterion for the existence of preprojective components.