The Chaucer Review: An Indexed Bibliography (Vols. 1-30)

Nitecki, Alicia K. "The Convention of the Old Man's Lament in the Pardoner's Tale." 16 (1981): 76-84.
The three rioters treat the old man in accordance with the traditional methods of treating the elderly. Traditionally the old either wait eagerly for death or dread it passionately. Chaucer changes the position of the old man: he cannot die because a corrupt world rejects him. The old man, then, should act as a warning figure, a demonstration of the horror of life without death.

Rowland, Beryl. "The Three Ages of The Parlement of the Three Ages." 9 (1975): 342-52.
The three ages were generally considered 30, 60, and 100, though 60 was considered very old. Using these traditional ages allows the poet to include the moral and spiritual significance of those ages in the irony which runs throughout the text.