A bilocal singularly perturbed problem is solved using Galerkin’s method in a space in which the test functions are weighted primitives of wavelets. This method provides a “good” numerical solution of this problem.
A.C. Mureşan, C. Mustăţa, A Galerkin Methods for a singularly perturbed bilocal problem, Bull. Şt. Univ. Baia Mare, Seria B, Fascicola Matematică-informatică, 15 (1999) nos. 1-2, 89-102, https://www.jstor.org/stable/44001741
Buletinul ştiinţific al Universitatii Baia Mare,
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 I. Daubechies, Orthonormal bases of compactly supported wavelets. Comm. pure Appl. Math. 41 (1998), pp. 909-996.
 R. Głowiński, W.N. Lawton, M. Ravachol, E. Tenenbaum, Wavelets solution of linear and nonlinear elliptic, parabolic and hyperbolic problems in one space dimension. In: R. Głowiński, A. Lichnewsky, ads., Computing Methods in Applied Sciences and Engineering, SIAM, Philadelphia (1990), pp. 55-120.
 P.W. Hemker, A numerical study of stiff two-point boundary problems, Amsterdam, 1997.
 J.-C. Xu, W.-C. Shann, Galerkin – wavelet methods for two point boundary value problems. Numer. Math., 63 (1992), pp. 123-142.
 H. Yserentant, On the multi – level splitting of finite element spaces. Numer. Math. 49 (1986), pp. 379-412.