  Poisson sigma models represent an interesting use of Poisson manifolds for
the construction of a classical field theory. Their definition in the language
of fibre bundles is shown and the corresponding field equations are derived
using a coordinate independent variational principle. The elegant form of
equations of motion for so called Poisson-Lie groups is derived. Construction
of the Poisson-Lie group corresponding to a given Lie bialgebra is widely known
only for coboundary Lie bialgebras. Using the adjoint representation of Lie
group and Drinfel'd double we show that Poisson-Lie group can be constructed
for general Lie bialgebra.
