^Souvenir of the Autumnal Meetings (October 1901, Manchester) of the Congregational Union of England, Wales, Scotland and Ireland, (10): 157, 1, Lancashire, Faces & Places., ottobre 1901.
^ Lee, Sidney (a cura di), "Mackennal, Alexander", in Dictionary of National Biography (2° supplemento), vol. 2, ed. (1912), Londra, Smith, Elder & Co..