APA
World of learning, . (1986). The world of learnings 36th ed. London: Europa.
Chicago
World of learning, . 1986. The world of learnings 36th ed. London: Europa.
Harvard
World of learning, . (1986). The world of learnings 36th ed. London: Europa.
MLA
World of learning, . The world of learnings 36th ed. London: Europa. 1986.