John XXIII, P. (1960). On the use of leisure time: Letter to Social Week of Italian Catholics, September 20, 1959. National Catholic Welfare Conference.
Lua i Stíl Chicago (17ú heag.)John XXIII, Pope. On the Use of Leisure Time: Letter to Social Week of Italian Catholics, September 20, 1959. Washington, D.C.: National Catholic Welfare Conference, 1960.
Lua MLA (8ú heag.)John XXIII, Pope. On the Use of Leisure Time: Letter to Social Week of Italian Catholics, September 20, 1959. National Catholic Welfare Conference, 1960.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.