by Giorgio Abetti; translated by J.B. Sidgwick. by Chsrles Rist ; translated by Jane Degras. by Georg Masing, translated by F. C. Thompson. by Ding Cong ; translated by Ma Mingtong by Guy Seguier ; translated by E. Griffin. by J.E. Pin ; translated by A. Howie. by Sigmund Freud ; translated by A. A. Brill. by Felix Klein ; translated by M. Ackerman. by Jean Dufay; translated by A.J. Pomerans. by Orazio Svelto ; translated by David C. Hanna.