A recent paper by Norm Craig, Emeritus Professor of Chemistry:
Craig, Norman C., Peter Groner, Andrew R. Conrad, Ranil Gurusinghe, Michael J. Tubergen.
Microwave spectra for the three C-13(1) isotopologues of propene and new rotational constants for propene and its C-13(1) isotopologues.
Journal of Molecular Spectroscopy, 328 1-6; 10.1016/j.jms.2016.07.002 OCT 2016.
Subscriber access at sciencedirect (post-publication). Access the pre-publication HTML version at
The SAO/NASA Astrophysics Data System.