1. On the linear ordinary q-difference equation;Adams;Annals of Math.,1929
2. Problems and prospects for basic hypergeometric functions;Andrews,1975
3. Les équations aux differences linéaires et les integrales des fonctions multiformes;Aomoto;J. Fac. Sci. Univ. Tokyo,1975
4. The generalized Riemann problem for linear differential and the allied problems for linear difference and q-difference equations;Birkhoff;Proc. Am. Acad. Arts and Sci.,1914
5. The general theory of linear q-difference equations;Carmichael;Amer. J. Math.,1912