[MSDN Library June 1998] WM_MDIDESTROY (55.7313892840209%)
MSDN Library Visual Studio 6.0 > Platform SDK > User Interface Services > Windowing > Multiple Document Interface > Multiple Document Interface Reference > MDI Messages
[MSDN Library April 2000] WM_MDIDESTROY (44.6202781729098%)
MSDN Library - April 2000 > Platform SDK > User Interface Services > Windows User Interface > Windowing > Multiple Document Interface > Multiple Document Interface Reference > Multiple Document Interface Messages