Harold C. Bryant
United States. National Park Service
1933-02-01
[Development of the naturalist program in the National Park Service : transcript, 1964 <a rel="nofollow" class="external free" href="https://archive.org/details/developmentnat00bryarich/page/n9/mode/1up">https://archive.org/details/developmentnat00bryarich/page/n9/mode/1up</a>]