@unpublished{TUW-105027, author = {Langer, Erasmus}, title = {{F}undamentals about {S}urface {A}coustic {W}ave {P}ropagation}, year = {1989}, note = {invited; talk: {S}ymposium on {C}oupled {F}ields - {T}heory and {A}pplications, {Z}akopane; 1989-11-07 -- 1989-11-10} }