[MSDN Library June 1998] WM_DROPFILES (35.2281928597718%)

MSDN Library Visual Studio 6.0 > Platform SDK > User Interface Services > Shell and Common Controls > Windows Shell API > Shell Reference > Messages

[MSDN Library April 2000] WM_DROPFILES (33.3521002024291%)

MSDN Library - April 2000 > Platform SDK > User Interface Services > Windows Shell > Shell Reference > Shell Messages and Notifications