Haag, V. (1986). Challenge: A program for the mathematically talented (Teacher's ed.). Addison-Wesley.
Čikaški stil citiranja (17. izdanje)Haag, Vincent. Challenge: A Program for the Mathematically Talented. Teacher's ed. Menlo Park, Calif: Addison-Wesley, 1986.
MLA način citiranja (9. izdanje)Haag, Vincent. Challenge: A Program for the Mathematically Talented. Teacher's ed. Addison-Wesley, 1986.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.