@article{Pupin00
,author={Pupin, M.}
,title={Wave propagation over non-uniform electrical conductors}
,journal={Transactions of the American Mathematical Society}
,year=1994
,month={}
,volume={1}
,number={}
,pages={259}
,note={See Pipes, L.A., "Applied Mathematics for Engineers
and Physicists", page 287} }