Columbia subject headings:
Congregationalism--Wales--History.
Congregationalism.
Congregationalists--Wales--History.
Undeb yr Annibynwyr Cymraeg.
Wales--Church history.
Harvard subject headings:
Congregationalism--History.
Congregationalists--Wales--History.
Undeb yr Annibynwyr Cymraeg.
Wales--Church history.
Princeton subject headings:
Congregationalism--Wales--History.
Congregationalism.
Congregationalists--Wales--History.
Wales--Church history.