APA Баримт

(1990). Science year 1991: The world book annual science supplement: A review of Science and Technology During the 1990 School year. Оникс.

Чикаго маягийн жагсаалт

Science Year 1991: The World Book Annual Science Supplement: A Review of Science and Technology During the 1990 School Year. chicago: Оникс, 1990.

MLA ишлэл

Science Year 1991: The World Book Annual Science Supplement: A Review of Science and Technology During the 1990 School Year. Оникс, 1990.