Petrovskibi, A. (1984). Age-group and pedagogical psychology. Progress Publishers.
Lua i Stíl Chicago (17ú heag.)Petrovskibi, A.V. Age-group and Pedagogical Psychology. Moscow: Progress Publishers, 1984.
Lua MLA (9ú heag.)Petrovskibi, A.V. Age-group and Pedagogical Psychology. Progress Publishers, 1984.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.