Neugebauer, Franz A. Department of Organic Chemistry, Max Planck Institute for Medical Research, Max Planck Society;
http://www.sciencedirect.com/science/article/pii/S0040402001931370/pdf?md5=217c225693a40ef484128c434fe89afe&pid=1-s2.0-S0040402001931370-main.pdf (Any fulltext)
https://doi.org/10.1016/S0040-4020(01)93137-0 (Any fulltext)
Neugebauer, F. A. (1970). Substituent effects in p-substituted 3-t-butyl-1,5-diarylverdazyls. Tetrahedron, 26(20), 4853-4857. doi:10.1016/S0040-4020(01)93137-0.