@misc{Kahlig_Peter_Note,
 author={Kahlig Peter and Matkowski, Janusz},
 howpublished={online},
 publisher={Wydaw. Politechniki Częstochowskiej},
 language={eng},
 title={Note on some infinite products for π},
 type={czasopismo},
 keywords={infinite product, Wallis-type product, Dido functional equation, Dido sequence, algebraic number, transcendential number, constructible number},
}