Further background reading can be found in R Allenby, Numbers and Proofs; M Liebeck, A Concise Introduction to Pure Mathematics; V Bryant, Yet Another Introduction to Analysis; R Bartle & D Sherbert, ...
T Gowers Mathematics: a very short introduction (Oxford University Press, 2002) M Liebeck A Concise Introduction to Pure Mathematics (Chapman & Hall/CRC Mathematics, 2005) Here, you can check our ...