Chapter XIII - XV. Simultaneous differential equations. Partial differential equations. Equations of the second order.
A Treatise on Differential Equations Hauptbd., GDML_Books, (1859), p. 287 / Harvested from
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@article{PPN585192030+DMDLOG_0009,
     title = {Chapter XIII - XV. Simultaneous differential equations. Partial differential equations. Equations of the second order.},
     booktitle = {A Treatise on Differential Equations Hauptbd.},
     series = {GDML\_Books},
     publisher = {Macmillan},
     year = {1859},
     pages = {287},
     url = {http://dml.mathdoc.fr/item/PPN585192030+DMDLOG_0009}
}

 (éd.). Chapter XIII - XV. Simultaneous differential equations. Partial differential equations. Equations of the second order., dans A Treatise on Differential Equations Hauptbd., GDML_Books,  (1859), p. 287. http://gdmltest.u-ga.fr/item/PPN585192030+DMDLOG_0009/