Haken, H. (1997). Discrete Dynamics of Complex Systems. Discrete Dynamics in Nature and Society, 1997(), 1-8. https://doi.org/10.1155/S1026022697000022
Fung, T. C. (1989). Steady state solutions of nonlinear dynamic systems [doctoral dissertation, The University of Hong Kong]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0029-1812201200007376