1. For a bibliography and brief résumé of the work done in this field consult Wiman: “Endliche Gruppen linearer Substitutionen”, Encyklopädie der Mathematischen Wissenschaften, Bd. I, pp. 522–554.
2. Journal für Mathematik, 84 (1878), p. 89. The Theorem is as follows: every linear homogeneous group (G) inn variables has an abelian self-conjugate subgroup (F) of orderf, and the order ofG is λf, where λ is inferior to a fixed number which depends only uponn.
3. “On the Order of Linear Homogeneous Groups”, First and Second Paper, Transactions of the American Math. Society, 4 (1903), pp. 387–397, and 5 (1904), pp. 310–325. These papers shall be referred to hereafter by “L-GI” and “L-GII”, respectively.
4. Maschke, Math. Ann. 52 (1899), p. 363, and Loewy, Transactions of the American Math. Soc., 4 (1903), p. 44, have proved that if a group of finite order leaves invariant a plane (x=0), then it must also leave invariant the pencil 205-1.
5. «Sur les substitutions orthogonales etc.» Annales scientifiques de l'École Normale Supérieure, (3), T. 6 (1889), pp. 9–102.