@InCollection{Piechowiak:2003,
author
=
"M.Piechowiak",
title
=
"Hippel Ernst von",
pages
=
"493--496",
year
=
"2003",
booktitle
=
"Powszechna encyklopedia filozofii. T. 4: G-I ISBN: 839188001X",
publisher
=
"Polskie Towarzystwo Tomasza z Akwinu",
address
=
"Lublin",
}