@inbook{401688, title = {18 Introduction}, booktitle = {Linear Differential Transformations of the Second Order}, series = {GDML\_Books}, publisher = {The English Universities Press, Ltd.}, address = {London}, year = {1971}, pages = {[164]-165}, url = {http://dml.mathdoc.fr/item/401688} }
(éd.). 18 Introduction, dans Linear Differential Transformations of the Second Order, GDML_Books, (1971), pp. [164]-165. http://gdmltest.u-ga.fr/item/401688/