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| 0000919574-16-012108-index.html | 2016-03-23 16:34:39 | |
| 0000919574-16-012108.txt | 2016-03-23 16:34:39 | |
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| d7088793_20-f.htm | 1627641 | 2016-03-23 16:34:39 |
| d7088793_ex12-1.htm | 6052 | 2016-03-23 16:34:39 |
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| d7088793_ex15-2.htm | 2874 | 2016-03-23 16:34:39 |
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| d7088793_ex4-14.htm | 161282 | 2016-03-23 16:34:39 |
| d7088793_ex8-1.htm | 3340 | 2016-03-23 16:34:39 |
| FilingSummary.xml | 30501 | 2016-03-23 16:34:39 |
| Financial_Report.xlsx | 69523 | 2016-03-23 16:34:39 |
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| nat-20151231.xsd | 60452 | 2016-03-23 16:34:39 |
| nat-20151231_cal.xml | 66073 | 2016-03-23 16:34:39 |
| nat-20151231_def.xml | 299645 | 2016-03-23 16:34:39 |
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| report.css | 2767 | 2016-03-23 16:34:39 |
| Show.js | 1410 | 2016-03-23 16:34:39 |