Central projective quaternionic representations

We obtain all the irreducible not similar central quaternionic projective r epresentations of a finite group G from the knowledge of the vector, comple x irreducible representations of suitable extensions of G, and classify the m according to a generalized Frobenius-Schur classification. Finally, a def inition of equivalence of such representations is proposed. (C) 2000 Americ an Institute of Physics. [S0022-2488(00)02412-9].