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| 0001564590-18-027095-index.html | 2018-11-06 07:51:24 | |
| 0001564590-18-027095.txt | 2018-11-06 07:51:24 | |
 0001564590-18-027095-xbrl.zip | 106847 | 2018-11-06 07:51:24 |
| atra-10q_20180930.htm | 1790017 | 2018-11-06 07:51:24 |
| atra-20180930.xml | 1275213 | 2018-11-06 07:51:24 |
| atra-20180930.xsd | 38275 | 2018-11-06 07:51:24 |
| atra-20180930_cal.xml | 41383 | 2018-11-06 07:51:24 |
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| atra-20180930_lab.xml | 324159 | 2018-11-06 07:51:24 |
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| atra-ex311_12.htm | 16130 | 2018-11-06 07:51:24 |
| atra-ex312_11.htm | 16155 | 2018-11-06 07:51:24 |
| atra-ex321_9.htm | 7425 | 2018-11-06 07:51:24 |
| FilingSummary.xml | 24899 | 2018-11-06 07:51:24 |
| Financial_Report.xlsx | 52729 | 2018-11-06 07:51:24 |
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| report.css | 2767 | 2018-11-06 07:51:24 |
| Show.js | 1085 | 2018-11-06 07:51:24 |