Scholtz, Gerhard; Kamenz, Carsten (2006). "The book lungs of Scorpiones and Tetrapulmonata (Chelicerata, Arachnida): Evidence for homology and a single terrestrialisation event of a common arachnid ancestor". Zoology. 109 (1): 2–13. doi:10.1016/j.zool.2005.06.003. PMID16386884.
Scholtz, Gerhard; Kamenz, Carsten (2006). "The book lungs of Scorpiones and Tetrapulmonata (Chelicerata, Arachnida): Evidence for homology and a single terrestrialisation event of a common arachnid ancestor". Zoology. 109 (1): 2–13. doi:10.1016/j.zool.2005.06.003. PMID16386884.