[MSDN Library June 1998] WM_QUERYOPEN (52.6275917065391%)
MSDN Library Visual Studio 6.0 > Platform SDK > User Interface Services > Windowing > Windows > Window Reference > Window Messages
[MSDN Library April 2000] WM_QUERYOPEN (52.6275917065391%)
MSDN Library - April 2000 > Platform SDK > User Interface Services > Windows User Interface > Windowing > Windows > Window Reference > Window Messages