APA
Houghton Mifflin Company, . (1990). Houghton Mifflin English. U.S.A: Houghton Mifflin Company.
Chicago
Houghton Mifflin Company, . 1990. Houghton Mifflin English. U.S.A: Houghton Mifflin Company.
Harvard
Houghton Mifflin Company, . (1990). Houghton Mifflin English. U.S.A: Houghton Mifflin Company.
MLA
Houghton Mifflin Company, . Houghton Mifflin English. U.S.A: Houghton Mifflin Company. 1990.
