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| 0001564590-18-018263-index.html | 2018-08-01 08:21:32 | |
| 0001564590-18-018263.txt | 2018-08-01 08:21:32 | |
 0001564590-18-018263-xbrl.zip | 105713 | 2018-08-01 08:21:32 |
| atra-10q_20180630.htm | 1826698 | 2018-08-01 08:21:32 |
| atra-20180630.xml | 1290376 | 2018-08-01 08:21:32 |
| atra-20180630.xsd | 38276 | 2018-08-01 08:21:32 |
| atra-20180630_cal.xml | 39150 | 2018-08-01 08:21:32 |
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| atra-20180630_lab.xml | 323913 | 2018-08-01 08:21:32 |
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| atra-ex103_6.htm | 367112 | 2018-08-01 08:21:32 |
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| atra-ex311_11.htm | 16128 | 2018-08-01 08:21:32 |
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| atra-ex321_7.htm | 7418 | 2018-08-01 08:21:32 |
| FilingSummary.xml | 24899 | 2018-08-01 08:21:32 |
| Financial_Report.xlsx | 51564 | 2018-08-01 08:21:32 |
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| report.css | 2767 | 2018-08-01 08:21:32 |
| Show.js | 1410 | 2018-08-01 08:21:32 |