APA
Lenz A. C., Kozłowska-Dawidziuk A. & National Research Council Canada. (2004). Ludlow and Pridoli (Upper Silurian) graptolites from the Arctic Islands, Canada. Ottawa: NRC Research Press.
Chicago
Lenz Alfred C, Kozłowska-Dawidziuk Anna and National Research Council Canada. 2004. Ludlow and Pridoli (Upper Silurian) graptolites from the Arctic Islands, Canada. Ottawa: NRC Research Press.
Harvard
Lenz A. C., Kozłowska-Dawidziuk A. and National Research Council Canada. (2004). Ludlow and Pridoli (Upper Silurian) graptolites from the Arctic Islands, Canada. Ottawa: NRC Research Press.
MLA
Lenz Alfred C, Kozłowska-Dawidziuk Anna and National Research Council Canada. Ludlow and Pridoli (Upper Silurian) graptolites from the Arctic Islands, Canada. Ottawa: NRC Research Press. 2004.