Tauberian Constants Connected with the Prime Number Theorem II: Computational Aspects. Harry Gretton, Ken Jukes (1978/1979) Mathematische Zeitschrift
Trauberian Constants Connected with the Prime Number Theorem. Ken A. Jukes (1975) Mathematische Zeitschrift
Two elementary proofs of Halász's theorem. Karl-Heinz Indlekofer, Hédi Daboussi (1992) Mathematische Zeitschrift