Gregorio, H. C. (1960). Principles and methods of teaching (Rev. ed.). R. P. Garcia Pub. Co.
Chicago Style aipamenaGregorio, Herman C. Principles and Methods of Teaching. Rev. ed. Quezon City: R. P. Garcia Pub. Co, 1960.
MLA aipamenaGregorio, Herman C. Principles and Methods of Teaching. Rev. ed. R. P. Garcia Pub. Co, 1960.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.