Then the principal, “chaotic”, spirals extend beyond corotation.
Patsis P.A. 2012, 'Mechanisms based on chaotic flows that support structures in barred-spiral systems',EPJ Web of Conferenceshttp://dx.doi.org/10.1051/epjconf/20121907003. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)