Cita APA
(1990). The 1990 world book year book.: The annual supplement to the world book encyclopedia (ed.). World book, Inc..
Citación estilo Chicago
The 1990 World Book Year Book.: The Annual Supplement to the World Book Encyclopedia. ed. Chicago: World book, Inc., 1990.
Cita MLA
The 1990 World Book Year Book.: The Annual Supplement to the World Book Encyclopedia. ed. World book, Inc., 1990.
Warning: These citations may not always be 100% accurate.