Using continuation theorems of Leray-Schauder degree theory, we obtain existence results for the first order quasilinear boundary value problem (Φ(u))=f (t,u), u(T)=bu(0), where Φ : R → (-a,a) is an homeomorphism such that Φ(0)= 0 and f :[0.T] × R → R is a continuous function, a and T being positive real numbers and b some non zero real number.
Bouchez, V., & Mawhin, J. (2014). Boundary value problems for a class of first order quasilinear ordinary differential equations. Portugaliae Mathematica, 71(3-4), 217-247. https://doi.org/10.4171/PM/1951 (Original work published 2014)