Zhang, Binlin, Giovanni Molica Bisci, and Mingqi Xiang. 2016. “Multiplicity Results for Nonlocal Fractional $p$-Kirchhoff Equations via Morse Theory”. Topological Methods in Nonlinear Analysis 49 (2):445-61. https://apcz.umk.pl/TMNA/article/view/TMNA.2016.081.