Giulianotti, Richard (1999). Football: A Sociology of the Global Game. John Wiley & Sons. p. 18. ISBN9780745617695. «Historically Rangers have maintained a staunch Protestant and anti-Catholic tradition which includes a ban on signing Catholic players.»
Gallagher, Tom (1987). Glasgow, the Uneasy Peace: Religious Tension in Modern Scotland, 1819–1914. Manchester University Press ND. p. 300. ISBN9780719023965. Consultado el 18 de agosto de 2012. (requiere registro). «The conflict in Ireland failed to be the catalyst which swept the religious cobwebs from the Ibrox-based club's terraces and boardroom. One of its managers even had no qualms in the 1970s about urging his players to roar out the loyalist battle-cry 'No Surrender' as they ran up the tunnel at Ibrox.»
Souness, Graeme; Gallacher, Ken (1989). Graeme Souness: A Manager's Diary. Mainstream Publishing. p. 17. ISBN9781851582242. «For years Rangers have been pilloried for what the majority of people saw as discrimination against one section of the population. Now we have shown that this unwritten policy at Ibrox is over. It's finished. Done with.»
McGill, Craig (4 de noviembre de 2001). «How Mo was sold out by a sports firm». Sunday Mirror. Consultado el 27 de marzo de 2009 – via FindArticles.com.
national-football-teams.com
«Mo Johnston». National Football Teams. Consultado el 2 de enero de 2021.
