PAP smear is invented by :

Routine cytological screening or Pap smear should be offered to all women above the age of 21 years who are sexually active for at least 3 years.In all women with abnormal Pap tests showing mild dysplasias, it is impoant to treat any accompanying inflammatory pathology and repeat the Pap test. If it persists to be abnormal, colposcopic examination are to be considered. Shaw's Textbook o gynaecology 16th edition page 488