J. Friedrich, S. Scheifele, A. Verl, and A. Lechler. Procedia \CIRP\, (2015)9th \CIRP\ Conference on Intelligent Computation in Manufacturing Engineering - \CIRP\ \ICME\ '14.
E. Westk�mper. CIRP Annals Manufacturing Technology : Annals of the International Academy for Production Engineering = Annales du Coll�ge International pour la Recherche en Productique = Berichte der Internationalen Akademie f�r Produktionstechnik, 56 (1):
419-422(2007)