1. Mechel, F.P. “Schallabsorber”, Vol. II, Chapter 10: “Sound in capillaries” S.Hirzel Verlag, Stuttgart, 1995
2. Mechel, F.P. “Schallabsorber”, Vol. III, Chapter 26: “Rectangular duct with local lining” S.Hirzel Verlag, Stuttgart, 1998
3. Mechel, F.P. “Schallabsorber”, Vol. III, Chapter 27: “Rectangular duct with lateral lining” S.Hirzel Verlag, Stuttgart, 1998
4. Mechel, F.P. “Schallabsorber”, Vol. III, Chapter 28: “Rectangular duct with unsymmetrical lining” S.Hirzel Verlag, Stuttgart, 1998
5. Mechel, F.P. “Schallabsorber”, Vol. III, Chapter 29: “Silencers with circular ducts” S.Hirzel Verlag, Stuttgart, 1998