Fischer, Herbert Max Planck Institute for Medical Research, Max Planck Society;
http://pubs.acs.org/doi/pdf/10.1021/ja01012a004 (Any fulltext)
https://doi.org/10.1021/ja01012a00410.1021/ja01012a004 (Any fulltext)
Gordon, M. S., & Fischer, H. (1968). A molecular orbital study of the isomerization mechanism of diazacumulenes. Journal of the American Chemical Society, 90(10), 2471-2476. doi:10.1021/ja01012a004.