On a Functional Equation Related to Iteration (Short Communication) JOHN LAMPERTI; GEORGE O'BRIEN — 1971 Aequationes mathematicae
On a Functional Equation Related to Iteration. John Lamperti; George O'Brien — 1972 Aequationes mathematicae
A Discrete Renewal Theorem with Infinite Mean. John Lamperti; Adriano Garsia Commentarii mathematici Helvetici