[Words from the editor].
Krzysztof J
KJ
Filipiak
D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000209:etiology*; D002648:Child; D004452:Echocardiography / Q000592:standards; D006801:Humans; D008193:Lyme Disease / Q000150:complications; D011044:Poland; D012955:Societies, Medical / Q000592:standards