Kutschera, Ulrich (децембар 2003). „A comparative analysis of the Darwin-Wallace papers and the development of the concept of natural selection”. Theory in Biosciences. Jena; Berlin & Heidelberg: Urban & Fischer; Springer-Verlag. 122 (4): 343—359. ISSN1431-7613. doi:10.1007/s12064-003-0063-6.
Barbieri, Francisco D. (1989). „The origin of Metazoa and Weismann's germ line theory”. Rivista di Biologia. Pisa; Rome: Perugia Anicia Srl. 82 (1): 61—74. ISSN0035-6050. PMID2665023.
Kutschera, Ulrich (децембар 2003). „A comparative analysis of the Darwin-Wallace papers and the development of the concept of natural selection”. Theory in Biosciences. Jena; Berlin & Heidelberg: Urban & Fischer; Springer-Verlag. 122 (4): 343—359. ISSN1431-7613. doi:10.1007/s12064-003-0063-6.
Barbieri, Francisco D. (1989). „The origin of Metazoa and Weismann's germ line theory”. Rivista di Biologia. Pisa; Rome: Perugia Anicia Srl. 82 (1): 61—74. ISSN0035-6050. PMID2665023.