1. Pyridine and pyridine derivatives;Scriven,1996
2. Pyridine and Pyridine Bases, Chemical Economics Handbook Product Review;Johnson,1997
3. Heterocyclic compounds such as pyrroles, pyridines, pyrollidins, piperdines, indoles, imidazol and pyrazins
4. F.E. Cislak, W.R. Wheeler, US Patent 2,744,904 (1956), to Reilly Tar and Chemical.