Explicit Bounds for the Sum of Reciprocals of Pseudoprimes and Carmichael Numbers. - Jonathan Bayless; Paul Kinlaw (J. Integer Seq., 2017)

Lower Bounds for Numbers With Three Prime Factors. - Paul Kinlaw (Integers, 2019)

Sums over primitive sets with a fixed number of prime factors. - Jonathan Bayless; Paul Kinlaw; Dominic Klyve (Math. Comput., 2019)