Unbounded domains of normality

Let f be a transcendental entire function of order less than 1/2. We introduce the method of "self-sustaining spread" to study the components of the set of normality of such a function. We give a new proof of the fact that any preperiodic or periodic component of the set of normality of f is bounded. We obtain the same conclusion for a wandering domain if the growth rate of f is never too small.