Equivalence of differential operators -- Some unitarily equivalent differential operators with finite and infinite singularities -- The land beyond bessel: A survey of higher special functions -- Nonlinear two-point boundary value problems -- On nonlinear boundary value problems for an elliptic system in the plane -- Totally singular extensions of the Cauchy problem for a special class of partial derivative operators with distributional coefficients -- Complex extensions of a submanifold of solutions of the sine-gordon equation -- Remark on bifurcation problems with several parameters -- Asymptotic theory and deficiency indices for fourth and higher order self-adjoint equations: A simplified approach -- On the spectra of Schrödinger operators with a complex potential -- Non-modal eigenfunction expansions -- Asymptotic distribution of eigenvalues of elliptic operators on unbounded domains -- Generalized hyperanalytic function theory -- Some spectral gap results -- A regular left-definite eigenvalue problem with eigenvalue parameter in the boundary conditions -- Some topics in nonlinear wave propagation -- An ordering of oscillation types for y(n) + py = 0 -- Fundamental properties of the solutions of quasilinear differential equations of the fifth order -- Oscillation properties of weakly nonlinear differential equations -- On boundary integral equation methods in stationary electromagnetic reflection -- Norm inequalities for derivatives -- Fixed point theorems -- Automatic control of errors for invariant imbedding -- A bound for solutions of a fourth order dynamical system -- Reducibility of almost periodic linear systems -- Convergence of solutions of infinite delay differential equations with an underlying space of continuous functions -- On a system of non linear strongly coupled partial differential equations arising in biology -- Differential operators with discrete spectrum -- On spectral theory for the linear selfadjoint equation Fy = ?Gy -- Estimates for some free boundary problems -- A new proof of existence of similarity solutions -- Symmetry and bifurcation from multiple eigenvalues -- Convergence to a travelling wave in an initial-boundary value problem -- Geometric remarks on second order criteria for maxima and minima -- Variational methods and almost solvability of semilinear equations.