1. Helwig-Otto (2004) Arzneimittel, 10th ed. WVG Stuttgart
2. Pindur U, Otto C, Molinier M, Massa W (1991) Helv Chim Acta 74: 727; Eitel M, Pindur U (1990) J Org Chem 55: 5368; Pindur U, Pfeuffer L (1987) Heterocycles 26: 325
3. Bodtke A, Otto H-H (2004) Pharmazie (submitted);
4. Sultani A, Dietrich H, Richter F, Otto H-H (2004) Monatsh Chem (submitted)
5. Bleile M, Wagner T, Otto H-H (2004) Helv Chim Acta (submitted)