@book{401380,
title = {Linear Differential Transformations of the Second Order},
series = {GDML\_Books},
publisher = {The English Universities Press, Ltd.},
address = {London},
year = {1971},
mrnumber = {MR0463539},
zbl = {0222.34002},
language = {en},
url = {http://dml.mathdoc.fr/item/401380}
}
Borůvka, Otakar. Linear Differential Transformations of the Second Order. GDML_Books (1971), http://gdmltest.u-ga.fr/item/401380/