APA (7th ed.) Citation
(1993). <The> 1993 world book year book: <the> annual supplement to The World Book Encyclopedia. World Book.
Chicago Style (17th ed.) Citation
<The> 1993 World Book Year Book: <the> Annual Supplement to The World Book Encyclopedia. Chicago: World Book, 1993.
MLA (9th ed.) Citation
<The> 1993 World Book Year Book: <the> Annual Supplement to The World Book Encyclopedia. World Book, 1993.
Warning: These citations may not always be 100% accurate.