1. The Asymmetric Rotor I. Calculation and Symmetry Classification of Energy Levels
2. �ber die Eigenwerte des asymmetrischen Kreisels
3. (a) ; ; ; ; ; ; In: ; eds. Concepts in Chemistry: A Contemporary Challenge; Research Studies Press: Somerset, UK, 1997; Chapter 9;
4. (b) ; ; Continuous symmetry and chirality measures. In: ed. Encyclopedia of Computational Chemistry; John Wiley & Sons: Chichester, UK, 1998; p 2890.
5. (a) In: Organic Chemical Crystallography; Consultants Bureau: New York, 1961; Chapter 4;