1951 ◽
Vol 47
(4)
◽
pp. 741-751
◽
1951 ◽
Vol 3
◽
pp. 335-338
◽
1976 ◽
Vol 56
(5)
◽
pp. 222-222
On the real solutions of systems of two homogeneous linear differential equations of the first order
1902 ◽
Vol 3
(2)
◽
pp. 196-196