Youngken, H. W. (2003). Natural drugs: Morphologic and taxonomic consideration (2nd ed.). Biotech books.
Čikaški stil citiranjaYoungken, Heber Wilkinson. Natural Drugs: Morphologic and Taxonomic Consideration. 2nd ed. Delhi: Biotech books, 2003.
MLA način citiranjaYoungken, Heber Wilkinson. Natural Drugs: Morphologic and Taxonomic Consideration. 2nd ed. Biotech books, 2003.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.