APA

(1992). Mcgraw Hill Encyclopeadia Of Science And Technolgy. V19. Ulc-Zyg. Ed 7. : .

Chicago

1992. Mcgraw Hill Encyclopeadia Of Science And Technolgy. V19. Ulc-Zyg. Ed 7. : .

Harvard

(1992). Mcgraw Hill Encyclopeadia Of Science And Technolgy. V19. Ulc-Zyg. Ed 7. : .

MLA

Mcgraw Hill Encyclopeadia Of Science And Technolgy. V19. Ulc-Zyg. Ed 7. : . 1992.