Diagram in novel Krishna Kanta's Will
<a href="https://en.wikipedia.org/wiki/Bankim_Chandra_Chattopadhyay" class="extiw" title="w:Bankim Chandra Chattopadhyay">w:Bankim Chandra Chattopadhyay</a>
1895
<a rel="nofollow" class="external text" href="http://dspace.gipe.ac.in/xmlui/handle/10973/23504">Gokhale Institute of Politics and Economics Digitised Books</a>