Symmetry Groups of Partial Differential Equations, Separation of Variables, and Direct Integral Theory
1994 ◽
Vol 125
(2)
◽
pp. 452-479
◽
2018 ◽
pp. 337-373
2013 ◽
Vol 2013
◽
pp. 1-8
2015 ◽
Vol 21
(4)
◽
pp. 285-318
◽
1995 ◽
Vol 6
(3)
◽
pp. 265-286
◽
1979 ◽
Vol 14
(4)
◽
pp. 497-542
◽