[MSDN Library June 1998] WM_MDIACTIVATE (45.4963584273929%)

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_MDIACTIVATE (41.20995995996%)

MSDN Library - April 2000 > Platform SDK > User Interface Services > Windows User Interface > Windowing > Multiple Document Interface > Multiple Document Interface Reference > Multiple Document Interface Messages