Rabbi Avraham Yitzchak HaLevy Zimmerman

HaRav Avraham Yitzchak Halevi Zimmerman, zt”l, learned in the yeshivos of Lita. After his marriage, he became the Rav of Halosk and then Rav of Krementchug. His son in law R' Boruch Ber Leibowitz took over his position when he left Hlusk, and later in Krementchug after his death. He was known to be completely immersed in his learning, and wore his tallis and tefillin all day.

https://hebrewbooks.org/36015

https://beta.hebrewbooks.org/pagefeed/hebrewbooks_org_53510_855.pdf

https://www.jewishgen.org/yizkor/slutsk/slu186.html

https://hamodia.com/columns/day-history-5-kislevnovember-23/

Haskama that he wrote for his brother in law's writings (R' Yitzchak Yaakov Varonovski), published by his nephews in 1905: https://hebrewbooks.org/pdfpager.aspx?req=1824&st=&pgnum=2