Man pages matching name xmvacreatemanagedtabstack in section 3:

XmVaCreateManagedTabStack.3.en	debian 10 / libmotif-dev
XmVaCreateManagedTabStack.3.en	debian 11 / libmotif-dev
XmVaCreateManagedTabStack.3.en	debian 12 / libmotif-dev