Hermit and Townsend's Warblers from <i>Bird-Lore, Vol. VI, No. 6.</i>
<bdi><a href="https://en.wikipedia.org/wiki/en:Louis_Agassiz_Fuertes" class="extiw" title="w:en:Louis Agassiz Fuertes"><span title="United States ornithological artist (1874-1927)">Louis Agassiz Fuertes</span></a>
</bdi>
<a rel="nofollow" class="external text" href="https://archive.org/details/birdlore61904nati">The Internet Archive</a>