Map 2. <i>Pinus koraiensis</i> &amp; <i>Pinus krempfii</i> range map
William B. Critchfield &amp; Elbert L. Little, Jr., U.S. Department of Agriculture &amp; Forest Service
<a rel="nofollow" class="external text" href="https://www.biodiversitylibrary.org/bibliography/66393#/summary"><i>Geographic distribution of the pines of the world</i>, Miscellaneous publication no. 991. U.S. Department of Agriculture &amp; Forest Service, Washington D.C., February, 1966</a>