Ramanujan theta function

Gregory V., "Approximations and Complex Multiplication According to Ramanujan", in Ramanujan Revisited (G.E. Andrews et al. Eds), Academic Press, 1988, pp 375–396

ancient India by R. Sridharan（页面存档备份，存于互联网档案馆） Combinatorial methods in ancient India （页面存档备份，存于互联网档案馆） Mathematics before S. Ramanujan （页面存档备份，存于互联网档案馆）