[1] Vlček V.:
The first conjugate point of solution of the N-th order iterated differential equation. Acta UP Olom., F. R. N., Tom 73, 1982.
MR 0702611 |
Zbl 0522.34029
[2] Borůvka O.:
Lineare Differentialtransformationen 2. Ordnung. VEB Deutscher Verlag der Wissenschaften, Berlin, 1967.
MR 0236448
[3] Sherman T. L.:
Properties of solutions of Nth order linear differential equations. Pacific J. Math., Vol. 15, No. 3, 1965.
MR 0185185 |
Zbl 0132.31204
[4] Vlček V.:
Conjugate points of solutions of a fourth-order iterated linear differential equation. Acta UP Olom., F. R. N., Tom 53, 1977.
MR 0594951
[5] Vlček V.:
On a distribution of zeros of solutions of a fourth-order iterated linear differential equation. Acta UP Olom., F. R. N., Tom 57, 1978.
MR 0554040