Interesting and usefull links

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Book directories
AMS books online 
Online Books and lecture notes in mathematics 
Cornell University historical mathematics book collection 
EMIS Math Monographs 
University of Michigan historical mathematics collection 

Math. books
Diestel: Graph Theory 
Cahn: Semi-simple Lie Algebras 
Martinez: Introduction to universal algebra 
Fundamentals of Model Theory 
A Course in Universal Algebra 
Bell: Modern Algebra 
Ash: Abstract Algebra 
Hatcher: Algebraic Topology 
Viro, Ivanov, Netsvetaev, Kharlamov: Elementary Topology - A First Course. Textbook in Problems 
Cain: Complex Analysis 
Cain, Herod: Multivariable Calculus 
Fremlin: Measure theory 

Lecture notes
Hart: Set theoretic methods in general topology 

Acta mathematica universitatis comenianesince 1991
Algebra universalis 
Algebraic and geometric topology 
Annals of math 
Annals of pure and applied Logic 
Applied Sciences 
Archivum mathematicumsince 1992
Bulletin of Symbolic Logic 
Bulletin of the AMS 
Canadian Journal of Mathematicssince 1997
Contributions to alg. and geom. 
Documenta mathematicasince 1996
Electronic research announcements of the AMS 
Forum Geometricorum 
Fundamentalnaja i prikladnaya matematika (Fundamental and applied mathematics)in Russian
Furman University electronic journal of undergradute math 
Geometry and topology 
Homology, homotopy and applications 
Indiana University Mathematics Journal 
International journal of math 
International Journal of Math and Math. Sciences 
International Mathematical News 
Izvestiya of the TSU. Series Mathematics. Mechanics. Informatics 
Journal of formalized mathematics 
Journal of recreational Math 
Journal of the AMS 
Journal of the australian MS 
Journal of the Australian Math. Soc., Series B Electronic 
Lecture Notes of TICMI (Tbilisi International Centre of Mathematics and Informatics) 
Lobachevskij J. of Math. 
Matematicki vestnik 
Mathematica Bohemicasince 1995
Mathematical proceedings of the Royal Irish Academy 
Math. Research Letters 
Pacific journal of mathsince 1997
Proceedings of the AMS 
Rendiconti istit. mat. univ. Triestesince 25(1993)
Renediconti del Circolo Matematico di Palermo 
Renediconti del Seminario Matematico di Padova 
Semigroup forum 
Theory and application of categoriessince 1995
Topology and its Applications 
Transactions of the AMSsince 1996
Ulam Quarterly Journal 

Journal directories
JSTORJSTOR contains older issues of these Journals: American Journal of Mathematics, American Mathematical Monthly, Annals of Mathematics, Analys, Journal of Symbolic Logic, Journal of the AMS, Mathematics of Computitaion, Proceedings of AMS, SIAM Journal on Applied Mathematics, SIAM Journal on Numerical Analysis, SIAM Review, Transactions of AMS (until 1997)
Jahrbuch project ( archive of the most important mathematical publications of the period 1868 -1942 
Czech math journalsAppl. Math., Czechoslovak Math. J., Mathematica Bohemica
EULER project (emis)This project shoud help with searching for math texts.

Papers of ...
Erdös, Hamilton, Riemann