Distribution Functions of the Sequence φ(M)/M, M ∈ (K, K+N] As K, N Go to Infinity. - Vladimír Baláz; Pierre Liardet; Oto Strauch (Integers, 2010)

Distribution functions of ratio sequences, IV. - Vladimír Baláz; Ladislav Misík; Oto Strauch; János T. Tóth (Period. Math. Hung., 2013)