34B05 Linear equations
34B10 Multipoint boundary value problems
34B15 Nonlinear boundary value problems
34B20 Weyl theory and its generalizations
34B24 Sturm-Liouville theory, See also {34Lxx}
34B27 Green functions
34B30 Special equations (Mathieu, Hill, Bessel, etc.)
34B99 None of the above but in this section