[1] J. H. Barrett:
A Prüfer transformation for matrix differential equations. Proc. Amer. Math Soc. 8 (1957), 510-518.
MR 0087821 |
Zbl 0079.10603
[2] R. Bellman:
Introduction to matrix analysis. McGгaw-Hill, New York.
Zbl 0872.15003
[3] O. Borůvka:
Lineaг differential transformations of the second order. Acad. Press, London 1971.
MR 0463539
[4] O. Došlý:
A phase matrix of lineaг diffeгential systems. Čas. pěst. mat. 110 (1985), 183-192.
MR 0796568
[5] O. Došlý:
The basic properties of the phase matгices of linear differential systems. Arch. Math. 21 (1985), 113-122.
MR 0817553
[6] O. Došlý:
On transformations of selfadjoint linear differential systems. Arch. Math. 21 (1985), 159-170.
MR 0833126
[7] O. Došlý:
On some properties of trigonometгic matrices. Čas. pěst. mat. 112 (1987),
MR 0897644
[8] G. J. Etgen:
Oscillation properties of certain nonlinear matrix differential equations of second order. Trans. Ameг. Math. Soc. 122 (1966), 289-310.
MR 0190421
[9] G. J. Etgen:
A note on trigonometric matгices. Proc. Amer. Math. Soc. 17 (1966), 1226 to 1232.
MR 0213646
[10] W. T. Reid:
A Prüfer transformation for differential systems. Pacific Ј. Math. 8 (1958), 575-584.
MR 0099474 |
Zbl 0102.30004