<P> It was subsequently found that the Czech serologist Jan Janský had independently pioneered the classification of human blood into four groups in 1907 , but Landsteiner 's independent discovery had been accepted by the scientific world while Janský remained then in relative obscurity . However , in 1921 an American medical commission acknowledged Janský 's classification . Jan Janský is nowadays credited with the first classification of blood into the four types ( I , II , III , IV ) . </P>
<P> It was subsequently found that the Czech serologist Jan Janský had independently pioneered the classification of human blood into four groups in 1907 , but Landsteiner 's independent discovery had been accepted by the scientific world while Janský remained then in relative obscurity . However , in 1921 an American medical commission acknowledged Janský 's classification . Jan Janský is nowadays credited with the first classification of blood into the four types ( I , II , III , IV ) . </P>
who proposed every person has specific blood group
who proposed every person has specific blood group
Czech serologist Jan Janský
Czech serologist Jan Janský