Impacting Education | University Library System, University of Pittsburgh. Cambridge University Press.
Čikaški stil citiranja (17. izdanje)Impacting Education | University Library System, University of Pittsburgh. Cambridge University Press.
MLA način citiranja (8. izdanje)Impacting Education | University Library System, University of Pittsburgh. Cambridge University Press.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.