Below are links to various countries with Ostrowiec societies/websites.

Israel
Israel

Jews of Ostrowiec Israel Facebook Page

Descendants of Jewish Ostrowiec Israel Facebook Page

Argentina flag

Yizkor book articles by Argentinian survivors

Brazil
Brazil

Descendentes de Judeus de Ostrowiec Facebook Page

Os notáveis descendentes brasileiros de Ostrowiec

Yizkor book articles by Brazilian survivors

Canada
Canada

Ostrovtser Society Toronto Facebook Page

Ostrovtser Shul in Toronto

Jewish Gen

Poland
Poland

Wojtek Mazan blog

Monika Pastuszko blog