[Epidemiological problems of pneumonia and bronchitis in children and infants].
D001991:Bronchitis / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D011014:Pneumonia / Q000453:epidemiology*; D011044:Poland; D012621:Seasons
Zagadnienia epidemiologiczne zapaleń płuc i oskrzeli u niemowlat.