Partial Differential Equations, Wave Equation
1992 ◽
Vol 437
(1901)
◽
pp. 673-692
◽
1986 ◽
Vol 27
(4)
◽
pp. 488-501
◽
1971 ◽
Vol 70
(3)
◽
pp. 455-465
2013 ◽
Vol 32
◽
pp. 55-60
◽
1943 ◽
Vol 61
(3)
◽
pp. 260-272
◽