John XXIII, P. (1960). On the use of leisure time: Letter to Social Week of Italian Catholics, September 20, 1959. N.C.W.C..
Dyfyniad Arddull ChicagoJohn XXIII, Pope. On the Use of Leisure Time: Letter to Social Week of Italian Catholics, September 20, 1959. Washington, D.C.: N.C.W.C., 1960.
Dyfyniad MLAJohn XXIII, Pope. On the Use of Leisure Time: Letter to Social Week of Italian Catholics, September 20, 1959. N.C.W.C., 1960.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.