“…When p = 2, the differential operator L is linear, and Mawhin's coincidence degree theory [13] can be applied, for example, see [2,3,8,9,15]. However, when p > 2, Mawhin's coincidence degree can no longer be applied directly, hence the Ge and Ren extension of the coincidence degree [4] becomes an efficient tool for the investigation, see [6,11,[17][18][19] and the references therein.…”