1. Lie, S. Über die Integration durch bestimmte Integrale von einer Klasse linearer partieller Differentialgleichungen. Archiv for Matematik og Naturvidenskab (Abbr Arch Math), vol. 6(3), 1881, p. 328–68; N.H. Ibragimov (Ed.), CRC handbook of lie group analysis of differential equations (Eng. Trans.), vol. 2, CRC Press, Boca Roton; 1995. Reprinted also in the book Lie group analysis: classical heritage, N.H. Ibragimov (Ed.), ALGA Publications, Karlskrona; 2004. p. 1–64.
2. Laplace type invariants for parabolic equations;Ibragimov;Nonlin Dyn,2002
3. Euler’s integration method for linear hyperbolic equations and its extension to parabolic equations;Ibragimov;Arch ALGA,2008
4. Extension of Euler’s method to parabolic equations;Ibragimov;Commun Nonlin Sci Numer Simul,2008
5. Singular invariant equation for the (1+1) Fokker–Planck equation;Johnpillai;J Phys A: Math General,2001