Get a Detailed Proof of Stirling's Formula

[Pratibha]

hey, can someone suggest where will a get a detailed proof of stirling's formula (related with gamma function). I read it from PRINCIPLES OF MATHEMATICAL ANALYSIS Walter Rudin,but in it many shortcut steps are there, which is either beyond my knowledge, or i m not getting it.

 

[Opalg]

hey, can someone suggest where will a get a detailed proof of stirling's formula (related with gamma function). I read it from PRINCIPLES OF MATHEMATICAL ANALYSIS Walter Rudin,but in it many shortcut steps are there, which is either beyond my knowledge, or i m not getting it.

The Wikipedia page on Stirling's formula gives two proofs. They are not completely free of shortcuts, but they provide links to details of all the missing steps.