Abtin Ataei^*, Mojtaba Nedaei, Reza Rashidi, Changkyoo Yoo^*, Optimum design of an off-grid hybrid renewable energy system for an office building, Journalof Renewable and Sustainable Energy (ISSN: 1941-7012, SCIE journal), 7(5), 053123:1-25, pp.- (2015.09) (Ack: NRF grant- MSIP- 2015R1A2A2A11001120)