Conway Zirkle Circa 1932-1935.
<span lang="en">Anonymous</span><span style="display:none">Unknown author</span>
Conway Zirkle". Embryo Project Encyclopedia (1932-1935). ISSN: 1940-5030 <a rel="nofollow" class="external free" href="http://embryo.asu.edu/handle/10776/3032">http://embryo.asu.edu/handle/10776/3032</a>.