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| 0001564590-19-001400.txt | 2019-01-30 16:21:23 | |
 0001564590-19-001400-xbrl.zip | 205805 | 2019-01-30 16:21:23 |
| extr-10q_20181231.htm | 2628116 | 2019-01-30 16:21:23 |
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| Financial_Report.xlsx | 96491 | 2019-01-30 16:21:23 |
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