q-Vertex operators for quantum affine algebras

$q$-vertex operators for quantum affine algebras have played important role in the theory of solvable lattice models and the quantum Knizhnik-Zamolodchikov equation. Explicit constructions of these vertex operators for most level one modules are known for classical types except for type $C_n^{(1)}$, where the level -1/2 have been constructed. In this paper we survey these results for the quantum affine algebras of types $A_n^{(1)}, B_n^{(1)}, C_n^{(1)}$ and $D_n^{(1)}$.