Some Global Properties of Matrices of Functions of One Variable. Y. SIBUYA — 1965 Mathematische Annalen
Stokes multipliers for subdominant solutions of second order differential equations with polynomial coefficients. Y. Sibuya; H.E. Gollwitzer — 1970 Journal für die reine und angewandte Mathematik
On asymptotic solutions of systems of nonlinear difference equations. W.A. Jr. Harris; Y. Sibuya — 1966 Journal für die reine und angewandte Mathematik