Electronic reproduction. [S.l.] : HathiTrust Digital Library, 2010.
Master and use copy. Digital master created according to Benchmark for Faithful Digital Reproductions of Monographs and Serials, Version 1. Digital Library Federation, December 2002. http://purl.oclc.org/DLF/benchrepro0212
Master and use copy. Digital master created according to Biodiversity Heritage Library Digital Imaging Specifications. http://biodivlib.wikispaces.com/Digital+Imaging+Specifications
Description based on: Vol. 33, no. 1 (Apr. 1919); title from PDF vol. page (Biodiversity Heritage Library, viewed Apr. 23, 2012).