Can you help me find a reference or explain how to find explicit Dehn twist generators for $MCG(D_n,\partial D_n)$, mapping class group of a $n$-punctured disc? (for the problem I am working on, $n=3,4$ would be sufficient).
PS: I asked a related question here:mapping class group of a 4-punctured sphere, which for $n=3$ discusses the relationship to the mapping class group of a torus. But I cannot find explicit Dehn twist generators based on that question at the moment (apparently Dehn twists about the curves $\alpha$ and $\beta$ there are two of the generators, but I do not know how that answer counts boundary Dehn twists as part of the generators).