Holt, James C.Magna Carta. Cambridge University Press, 1992. Originally published in 1965, this comprehensive study puts English politics in context.
Pallister, Anne.Magna Charta: The Heritage of Liberty. Oxford University Press, 1971. An interpretive study that traces the popular myths, realities, and political uses of the famous document.
Swindler, William F.Magna Carta: Legend and Legacy. Bobbs, 1965. History, significance, and text, with commentary on each clause.