6 Polar functions
Linear Differential Transformations of the Second Order, GDML_Books, (1971), p. [50]-64 / Harvested from
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@inbook{401675,
     title = {6 Polar functions},
     booktitle = {Linear Differential Transformations of the Second Order},
     series = {GDML\_Books},
     publisher = {The English Universities Press, Ltd.},
     address = {London},
     year = {1971},
     pages = {[50]-64},
     url = {http://dml.mathdoc.fr/item/401675}
}

 (éd.). 6 Polar functions, dans Linear Differential Transformations of the Second Order, GDML_Books,  (1971), pp. [50]-64. http://gdmltest.u-ga.fr/item/401675/