Der ikkje anna er nemnd er Engelskspråkleg Wikipedia: Sir George Clark, 3rd Baronet, https://en.wikipedia.org/wiki/Sir_George_Clark,_3rd_Baronet saman med John Harbinson: The Ulster Unionist Party 1882-1973. Its development and organisation. Belfast, Blackstaff Press 1973, s. 190. SBN 85640-076-9
