Square-Mile Cells that represent Proprietary Gas-producing Wells from Shale Intervals in the United States

https://energy.usgs.gov/OilGas/AssessmentsData/NationalOilGasAssessment.aspx.该链接指向美国地质调查局（United States Geological Survey, USGS）能源板块下的国家油气评估数据页面：https://energy.usgs.gov/OilGas/AssessmentsData/NationalOilGasAssessment.aspx。