[1] L.E. Dickson, History of the Theory of Numbers, Vol.II, Chelsea publishing company, New York, 1952.
[2] B. Batta and A.N. Singh, History of Hindu Mathematics, Asia Publishing House, 1938.
[3] M.A. Gopalan and S. Devibala, Integral solutions of the double equations x(y − k) = v 2 , y(x − h) = u 2 , IJSAC, 1(1 (2004) 53–57.
[4] M.A. Gopalan and S. Devibala, On the system of double equations x 2 − y 2 + N = u 2 , x2 − y 2 − N = v 2 , Bull. Pure Appl. Sci. 23(2) (2004) 279–280.
[5] M.A. Gopalan and S. Devibala, Integral solutions of the system a(x 2 −y 2 ) + N2 1 = u 2 , b(x 2 −y 2 ) + N2 2 = v 2 , ActaCiencia Indica XXXIM(2) (2005) 325–326.
[6] M.A. Gopalan and S. Devibala, Integral solutions of the system x 2 −y 2 +b = u 2 , a(x 2 −y 2 )+c = v 2, Acta Ciencia
Indica, XXXIM(2) (2005) 607.
[7] M.A. Gopalan and S. Devibala, On the system of binary quadratic diophantine equations a(x 2 − y 2 ) + N =u 2 b(x 2 − y2) + N = v2 , Pure Appl. Math. Sci. LXIII(1-2) (2006) 59–63.
[8] M.A. Gopalan, S. Vidhyalakshmi and K. Lakshmi, On the system of double equations 4x 2−y 2 = z2 , x2+2y 2 = w2, Scholars J. Engin. Technol. 2(2A) (2014) 103–104.
[9] M.A. Gopalan, S. Vidhyalakshmi and R. Janani, On the system of double Diophantine equations a0 + a1 =q2 , a0a1 ± 2(a0 + a1) = p 2 − 4, Trans. Math. 2(1) (2016) 22–26.
[10] M.A. Gopalan, S. Vidhyalakshmi and A. Nivetha, On the system of double Diophantine equations a0 + a1 =q2 , a0a1 ± 6(a0 + a1) = p2 − 36, Trans. Math. 2(1) (2016) 41–45.
[11] M.A. Gopalan, S. Vidhyalakshmi and E. Bhuvaneswari, On the system of double Diophantine equations a0+a1 =q2, a0a1 ± 4(a0 + a1) = p2 − 16, Jamal Academic Research Journal, Special Issue, 2016, 279–282.
[12] K. Meena, S. Vidhyalakshmi and C. Priyadharsini, On the system of double Diophantine equations a0 + a1 =q2 , a0a1 ± 5(a0 + a1) = p2 − 25, Open Journal of Applied and Theoretical Mathematics (OJATM), 2(1) (2016)8–12.
[13] M.A. Gopalan, S. Vidhyalakshmi and A. Rukmani, On the system of double Diophantine equations a0 − a1 =q2, a0a1 ± (a0 − a1) = p2 + 1 , Trans. Math. 2(3) (2016) 28–32.
[14] S. Devibala, S. Vidhyalakshmi, G. Dhanalakshmi, On the system of double equations N1 − N2 = 4k + 2(k >0), N1N2 (2k + 1)α 2 , International Journal of Engineering and Applied Sciences (IJEAS), 4(6) (2017) 44–45.