[MSDN Library June 1998] BM_GETSTATE (49.5210727969349%)
MSDN Library Visual Studio 6.0 > Platform SDK > User Interface Services > Controls > Buttons > Button Reference > Button Messages
[MSDN Library April 2000] BM_GETSTATE (49.5210727969349%)
MSDN Library - April 2000 > Platform SDK > User Interface Services > Windows User Interface > Controls > Buttons > Button Reference > Button Messages
[MSDN Library April 2000] BM_GETSTATE (42.0977011494253%)
MSDN Library - April 2000 > Windows CE Documentation > Application Development > API Reference > User Interface > Messages