@Article{49022,
journal="Klinika Oczna / Acta Ophthalmologica Polonica",
issn="0023-2157",
volume="106",
number="4",
year="2004",
title="Application of duo-systems (piggy back) 
in correction of keratoconus",
author="pages="629--632",
url="https://www.termedia.pl/Application-of-duo-systems-piggy-back-r-nin-correction-of-keratoconus,124,49022,1,1.html"
}