S. Koshitani et K. Waki, The Loewy structure of the projective modules of the Mathieu group M-12 and its automorphism group in characteristic 3, COMM ALGEB, 27(1), 1999, pp. 1-36
The Loewy and socle structure of the projective indecomposable modules for
the group algebras of the Mathieu group M-12 and its automorphism group M-1
2.2 over an algebraically closed field of characteristic 3 are determined w
ithout using computers.