Shanshan Chen, Zonghao Liu & Junping Shi. (1970). Nonexistence of Nonconstant Positive Steady States of a Diffusive Predator-Prey Model with Fear Effect.
            <i>Journal of Nonlinear Modeling and Analysis</i>. <i>1</i> (1).
            47-56.
         doi:10.12150/jnma.2019.47