New results are established here on the phase portraits and bifurcations of the kinematic model, first presented by H.K. Wilson, and by him attributed to L. Markus (unpublished). A new, self-sufficient, study which extends that of H.K. Wilson and allows an essential conclusion for the applicability of the model is reported here.
"On the motion under focal attraction in a rotating medium." Bull. Belg. Math. Soc. Simon Stevin 15 (5) 921 - 925, December 2008. https://doi.org/10.36045/bbms/1228486415