A third order differential equation
Tài liệu tham khảo
M. Bocher, Leçons sur les méthodes de Sturm (Paris, 1917).
S. Goldstein, “A note on the boundary layer equations”, Proc. Cambridge Philos. Society,35 (1939), 338–340.
G. H. Hardy, “A note on a differential equation”, Proc. Cambridge Philos. Society35 (1939), 652–653.