International Geological Congress Copenhagen, Denmark, & Sorgenfrei, T. (1960). Report of the twenty-first session, Norden: Denmark, Finland, Iceland, Norway, Sweden, 1960. Berlingske bogtr..
Čikaški stil citiranja (17. izdanje)International Geological Congress Copenhagen, Denmark, i Theodor Sorgenfrei. Report of the Twenty-first Session, Norden: Denmark, Finland, Iceland, Norway, Sweden, 1960. Copenhagen: Berlingske bogtr., 1960.
MLA način citiranja (8. izdanje)International Geological Congress Copenhagen, Denmark, i Theodor Sorgenfrei. Report of the Twenty-first Session, Norden: Denmark, Finland, Iceland, Norway, Sweden, 1960. Berlingske bogtr., 1960.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.