@PhdthesisMisc{P53_942, author = {Peter Henrici}, title = {Zur Funktionentheorie der Wellengleichung}, note = {Dis_no 2191, Prof. Dr. Eduard Stiefel}, school = {ETH Z{\"u}rich}, doi = {http://dx.doi.org/10.3929/ethz-a-000097995}, year = {1953} }