This work has become the standard introduction to the theory of p-adic numbers.
The 2nd edition adds a deeper treatment of p-adic functions, including the Iwasawa logarithm and the p-adic gamma-function, plus new exercises and an appendix of answers and hints.
Springer-verlag New York Inc. P-adic numbers, p-adic analysis, and zeta-functions, hardback/neal koblitz
