  The three-dimensional Schredinger's equation is analyzed with the help of the
correspondence principle between classical and quantum-mechanical quantities.
Separation is performed after reduction of the original equation to the form of
the classical Hamilton-Jacobi equation. Each one-dimensional equation obtained
after separation is solved by the conventional WKB method. Quasiclassical
solution of the angular equation results in the integral of motion $\vec
M^2=(l+\frac 12)^2\hbar^2$ and the existence of nontrivial solution for the
angular quantum number $l=0$. Generalization of the WKB method for
multi-turning-point problems is given. Exact eigenvalues for solvable and some
"insoluble" spherically symmetric potentials are obtained. Quasiclassical
eigenfunctions are written in terms of elementary functions in the form of a
standing wave.
