In "Recent Results on Generalized Baumslag-Solitar Groups," by D.J.S Robinson in Note Mat. 30 (2010) suppl. n. 1, 37–53, it is claimed that Kropholler [ . . . ] showed that there is a type of Tits alternative for GBS-groups, (Kropholler [11]). Here GBS-groups are generalised Baumslag-Solita...