Sikhim and adjoining territories (L. Austine Waddell, 1898), based on Survey of India maps of that time. It is known that the "Langmar River" is actually the Charitang River of Bhutan.
<a href="https://en.wikipedia.org/wiki/L._Austine_Waddell" class="extiw" title="w:L. Austine Waddell">L. Austine Waddell</a>
1898
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