  We present an interesting connection between Einstein-Friedmann equations for
the models of universe filled with scalar field and the special form of Abel
equation of the first kind. This connection works in both ways: first, we show
how, knowing the general solution of the Abel equation (corresponding to the
given scalar field potential) one can obtain the general solution of the
Friedman Equation (and use the former for studying such problems as existence
of inflation with exit for particular models). On the other hand, one can
invert the procedure and construct the B\"{a}cklund auto-transformations for
the Abel equation.
