Europa Publications & Europa Publications. (1969). The world of learning 1968-69 (19. ed.). Staples Printers Rochester.
Chicago Style (17th ed.) CitationEuropa Publications and Europa Publications. The World of Learning 1968-69. 19. ed. Rochester: Staples Printers Rochester, 1969.
MLA (9th ed.) CitationEuropa Publications and Europa Publications. The World of Learning 1968-69. 19. ed. Staples Printers Rochester, 1969.