The manuscript for the initial operating capabilities of the Multi-Radar Multi-Sensor (MRMS) quantitative precipitation estimation (QPE) products were published in the April 2016 edition of the Bulletin of the American Meteorological Society (BAMS) journal. You can read all about the MRMS QPE system here:
http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-14-00174.1