@phdthesis{Schmidt2002, author = {Schmidt, Frank}, title = {Solution of Interior-Exterior Helmholtz-Type Problems Based on the Pole Condition Concept}, year = {2002}, language = {en} } @phdthesis{Schmidt1989, author = {Schmidt, Frank}, title = {Ingenieurm{\"a}ßige Berechnung der Feldausbreitung in optischen Bauelementen der Lichtwellenleitertechnik}, year = {1989}, language = {en} }