Localities for these populations are reported by Pierce et al. Another author may misinterpret or misquote the original source, and if you rely on the second author for the information, you will be perpetuating the error. Occasionally, you may be unable to obtain the original source material. In this case you should make clear to your reader that you are relying on a secondary source for the information by giving a citation as shown below. This section should include only those references you actually cite in the paper.
Different journals have different styles for the references.
You may use the style given below, in which the authors are listed first, followed by the date, the title of the paper, and finally the journal where published. Berven, K. A., and D. E. Gill. Interpreting geographic variation in life-history traits. Wilbur, H. M. 1972. Competition, predation, and the structure of the Ambystoma-Rana sylvatica community.