Power Engineering, Mar. 2017, by S. Can Gülen, Ilya Yarinovsky, and Dave Ugolini.
http://www.power-eng.com/articles/print/volume-121/issue-3/features/a-cheaper-hrsg-with-advanced-gas-turbines.html

"Present state-of-the-art in gas turbine combined cycle (GTCC) design is three-pressure, reheat (3P-RHT) steam bottoming cycle with steam generation at three different pressure levels. The goal is to maximize total steam generation and steam turbine generator power output for a given gas turbine exhaust energy and, thus, to maximize combined cycle efficiency."