01093nam--2200349---450099000321829020331620090416090111.0000321829USA01000321829(ALEPH)000321829USA0100032182920090415d1976----km-y0ENGy0103----baengNL||||||||001yySingularly perturbed differential operators of second orderP. P. N. De GroenAmsterdamMathematisch Centrum1976IX, 159 P.ill.24 cmMathematical Centre Tracts682001Mathematical Centre TractsOperatori differenzialiBNCF515.7242DE GROEN,P.P.N.603588ITsalbcISBD990003218290203316510 MCT 6813744/CBS51000217064BKSCIRSIAV79020090415USA011553RSIAV79020090416USA010901Singularly perturbed differential operators of second order1011423UNISA