@book{PfeifferKnepper1999, author = {Pfeiffer, Johann and Knepper, Ludger}, title = {Diplom-Ingenieur/Diplom-Ingenieurin (Fachhochschule) Maschinenbau Energie- und W{\"a}rmetechnik}, publisher = {Bertelsmann}, address = {Bielefeld}, pages = {Losebl.-Ausg.}, year = {1999}, language = {de} } @book{KnepperPfeiffer1999, author = {Knepper, Ludger and Pfeiffer, Johann}, title = {Diplom-Ingenieur / Diplom-Ingenieurin (Fachhochschule) Maschinenbau, Energie- und W{\"a}rmetechnik}, publisher = {Bertelsmann}, address = {Bielefeld}, pages = {Loseblattausg.}, year = {1999}, language = {de} }