Cita APA (7a ed.)
(1990). Science Year 1991: The World Book Annual. Science Supplement. A review of Science and Technology During the 1990 School Year. The World Book,Inc.
Cita Chicago Style (17a ed.)
Science Year 1991: The World Book Annual. Science Supplement. A Review of Science and Technology During the 1990 School Year. Chicago: The World Book,Inc, 1990.
Cita MLA (9a ed.)
Science Year 1991: The World Book Annual. Science Supplement. A Review of Science and Technology During the 1990 School Year. The World Book,Inc, 1990.
Precaución: Estas citas no son 100% exactas.