Robert Gordon Bartholomew , of the sixth generation of cartographers , has extensively researched .
Robert Gordon Bartholomew , of the sixth generation of cartographers , has extensively documented the genealogy not only of his own branch of the family , but also of several other Bartholomew families .
Robert Gordon Bartholomew , of the sixth generation of cartographers , has extensively researched and documented the genealogy not only of his own branch of the family , but also of several other Bartholomew families .