I am looking for reference on Casselman-Shalika formula for GL(n) and PGL(n) at finite place p.



Reference on Casselman-Shalika formula for GL(n) and PGL(n)?
In [this paper](http://projecteuclid.org/DPubS?service=UI&version=1.0&verb=Display&handle=euclid.pja/1195518347), Shintani proves the Casselman-Shalika(-Shintani) formula for GL(n). This preceded Casselman-Shalika's [paper](http://www.numdam.org/item?id=CM_1980__41_2_207_0) by a few years. Several of [Cogdell's](http://www.math.osu.edu/~cogdell.1/) expository articles on L-functions have easy-to-read descriptions of the formula.


