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| 0000799233-18-000025-index.html | 2018-05-10 12:12:34 | |
| 0000799233-18-000025.txt | 2018-05-10 12:12:34 | |
 0000799233-18-000025-xbrl.zip | 154325 | 2018-05-10 12:12:34 |
| exhibit3112018q1.htm | 23570 | 2018-05-10 12:12:34 |
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| exhibit3212018q1.htm | 9715 | 2018-05-10 12:12:34 |
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| Financial_Report.xlsx | 53357 | 2018-05-10 12:12:34 |
| htld-20180331.xsd | 33523 | 2018-05-10 12:12:34 |
| htld-20180331_cal.xml | 59642 | 2018-05-10 12:12:34 |
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| report.css | 2767 | 2018-05-10 12:12:34 |
| Show.js | 1410 | 2018-05-10 12:12:34 |