Period variations the intermediate polars EX Hya, FO Aqr and RXS
  J180340.0+401214
  We present results of CCD photometric study of the intermediate polars FO
Aqr, EX Hya and RXS J180340.0+401214 = USNO-A2.0 1275-09738647 and
corresponding corrected ephemerids.
