Adriaan & Izaak van Ostade biography in De groote schouburgh der Nederlantsche konstschilders en schilderessen (1718) by Arnold Houbraken, courtesy of the Digital library for Dutch literature
One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Ostade s.v. Adrian Ostade". Encyclopædia Britannica. 20 (11th ed.). Cambridge University Press. pp. 355–356.