Outer automorphism groups of certain 1-relator groups

Residual finiteness of outer automorphism groups of certain 1-relator groups

“…Since Out(G) is residually finite (see [15]) for s > 0, we have the following conclusion: Problem. Are outer automorphism groups of conjugacy separable 1-relator groups residually finite?…”

Class-preserving automorphisms of certain HNN extensions

“…Using Grossman's result, outer automorphism groups of Fuchsian groups [1,12], most of Seifert 3-manifold groups [2] and certain 1-relator groups [9,10] are residually finite.…”