Normal fibrations of polyhedra, and duality

A duality theory is constructed in the category of stable finite fibrations over a finite polyhedron $X$. With the aid of this theory, a result is obtained about the stable characterization of the normal fibration of the polyhedron, in the class of finite reducible fibrations over $X$. As a corollary, the uniqueness theorem is proved for $\Lambda$-Spivak fibrations over $\Lambda$-Poincaré complexes, for an arbitrary commutative ring $\Lambda$. Also, a result is obtained concerning the space of stable self-equivalences of the fiber of the normal fibration of $X$.
Bibliography: 10 titles.