Swain, S; et al. (2017). „Application of SPI, EDI and PNPI using MSWEP precipitation data over Marathwada, India”. 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS). 2017. стр. 5505—5507. ISBN978-1-5090-4951-6. S2CID26920225. doi:10.1109/IGARSS.2017.8128250.
Wang, Qianfeng; Shi, Peijun; Lei, Tianjie; Geng, Guangpo; Liu, Jinghui; Mo, Xinyu; Li, Xiaohan; Zhou, Hongkui; Wu, Jianjun (2015). „The alleviating trend of drought in the Huang-Huai-Hai Plain of China based on the daily SPEI”. International Journal of Climatology. 35 (13): 3760—3769. Bibcode:2015IJCli..35.3760W. S2CID140703336. doi:10.1002/joc.4244.
Wang, Qianfeng; Shi, Peijun; Lei, Tianjie; Geng, Guangpo; Liu, Jinghui; Mo, Xinyu; Li, Xiaohan; Zhou, Hongkui; Wu, Jianjun (2015). „The alleviating trend of drought in the Huang-Huai-Hai Plain of China based on the daily SPEI”. International Journal of Climatology. 35 (13): 3760—3769. Bibcode:2015IJCli..35.3760W. S2CID140703336. doi:10.1002/joc.4244.
Swain, S; et al. (2017). „Application of SPI, EDI and PNPI using MSWEP precipitation data over Marathwada, India”. 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS). 2017. стр. 5505—5507. ISBN978-1-5090-4951-6. S2CID26920225. doi:10.1109/IGARSS.2017.8128250.
Wang, Qianfeng; Shi, Peijun; Lei, Tianjie; Geng, Guangpo; Liu, Jinghui; Mo, Xinyu; Li, Xiaohan; Zhou, Hongkui; Wu, Jianjun (2015). „The alleviating trend of drought in the Huang-Huai-Hai Plain of China based on the daily SPEI”. International Journal of Climatology. 35 (13): 3760—3769. Bibcode:2015IJCli..35.3760W. S2CID140703336. doi:10.1002/joc.4244.