A curve is called superelliptic if $y^n = (x-\alpha_1)^{d_1}...(x-\alpha_s)^{d_s}$ where $n \ge 2$ and $d_i > 0$.
From googling around, I found several papers which talk about these curves and mention facts about how the values $d_i,s$ and $n$ are related to the ramification degree of the normalization of the curve. For example, in the paper "Some Remarks on Cyclic Galois Coverings of the Projective Line over Finite Fields" by Christina Martinez and Alberto Besana, Remark 2.5.
Are there any standard references for these facts? I am especially interested in the case where the curve is defined over a non-algebraically closed field.