\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
The exactly and quasi-exactly solvable problems for spin one-half in one
dimension on the basis of a hidden dynamical symmetry algebra of Hamiltonian
are discused. We take the supergroup, OSP~$(2|1)$, as such a symmetry. A
number of exactly solvable examples are considered and their spectrum are
evaluated explicitly. Also, a class of quasi-exactly solvable problems on the
basis of such a symmetry has been obtained.
\end{document}