@PhdthesisMisc{R64_931,
author = {Roshdi Abdel-Rahman Amer},
title = {The Approximation problem of electrical filters},
note = {Dis_no 3399, Prof. Dr. Eduard Stiefel},
school = {ETH Z{\"u}rich},
doi = {http://dx.doi.org/10.3929/ethz-a-000099063},
year = {1964}
}