  In this work, we study some models of scalar fields in 1+1 dimensions with
non-linear self-interactions. Here, we show how it is possible to extend the
solutions recently reported in the literature for some classes of nonlinear
equations like the nonlinear Klein-Gordon equation, the generalized
Camassa-Holm and the Benjamin-Bona-Mahony equations. It is shown that the
solutions obtained by Yomba [1], when using the so-called auxiliary equation
method, can be reached by mapping them into some known nonlinear equations.
This is achieved through a suitable sequence of translation and power-like
transformations. Particularly, the parent-like equations used here are the ones
for the $\lambda \phi^4$ model and the Weierstrass equation. This last one,
allow us to get oscillating solutions for the models under analysis. We also
systematize the approach in order to show how to get a larger class of
nonlinear equations which, as far as we know, were not taken into account in
the literature up to now.
