\bib{1949/buchstab}
\yr 1949
\mr 11,84b
\by Aleksandr A. Buchstab
\paper On those numbers in an arithmetic progression all prime factors of which are small in order of magnitude
\jour Doklady Akademii Nauk SSSR
\issn 0002--3264
\vol 67
\pages 5--8
\endref