概素数
“Almost-primes in arithmetic progressions and short intervals”. Mathematical Proceedings of the Cambridge Philosophical Society 83 (3): 357–375. doi:10.1017/S0305004100054657. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=2079092&fileId=S0305004100054657.
↑ Michiel Hazewinkel, ed. (2012), Encyclopaedia of Mathematics, 1, Springer Science & Business Media, ISBN 9789401512398, https://books.google.com/books?id=IEnqCAAAQBAJ&pg=PA158&dq=%22almost+prime%22
↑ Tenenbaum, Gerald (1995). Introduction to Analytic and Probabilistic Number Theory. Cambridge University Press. ISBN 0-521-41261-7