  We have constructed new formulae for generation of solutions for the
nonlinear heat equation and for the Burgers equation that are based on
linearizing nonlocal transformations and on nonlocal symmetries of linear
equations. Found nonlocal symmetries and formulae of nonlocal nonlinear
superposition of solutions of these equations were used then for construction
of chains of exact solutions. Linearization by means of the Legendre
transformations of a second-order PDE with three independent variables allowed
to obtain nonlocal superposition formulae for solutions of this equation, and
to generate new solutions from group invariant solutions of a linear equation.
