Complex sentence: In January 1929, he was one of the instructors in a cryptology course organized by the Cipher Bureau, at Poznań University, which was attended by selected mathematics students, including future Cipher Bureau civilian employees Marian Rejewski, Jerzy Różycki and Henryk Zygalski.
Split into simpler sentences: In January 1929, he was one of the instructors in a cryptology course organized by the Cipher Bureau, at Poznań University, which was attended by selected mathematics students. They included future Cipher Bureau civilian employees Marian Rejewski, Jerzy Różycki and Henryk Zygalski.