| SC 13G/A | 2003-06-09 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 3,501,143 | 8.0% | EDGAR |
| SC 13G/A | 2003-02-14 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 5,750,711 | 13.3% | EDGAR |
| SC 13G/A | 2003-02-12 | WELLINGTON MANAGEMENT CO LLP | UNIT CORP | 789,400 | 1.8% | EDGAR |
| SC 13G/A | 2003-02-07 | DIMENSIONAL FUND ADVISORS INC | UNIT CORP | 1,093,450 | 2.5% | EDGAR |
| SC 13G | 2003-02-05 | ROYCE & ASSOCIATES LLC | UNIT CORP | 2,596,000 | 6.0% | EDGAR |
| SC 13G/A | 2002-02-14 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 5,717,679 | 15.9% | EDGAR |
| SC 13G/A | 2002-02-12 | DIMENSIONAL FUND ADVISORS INC | UNIT CORP | 1,916,000 | 5.3% | EDGAR |
| SC 13G | 2002-02-12 | WELLINGTON MANAGEMENT CO LLP | UNIT CORP | 2,100,700 | 5.8% | EDGAR |
| SC 13G/A | 2001-02-14 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 4,540,534 | 12.7% | EDGAR |
| SC 13G | 2001-02-02 | DIMENSIONAL FUND ADVISORS INC | UNIT CORP | 1,820,100 | 5.1% | EDGAR |
| SC 13G | 2001-02-02 | DIMENSIONAL FUND ADVISORS INC | UNIT CORP | 1,820,100 | 5.1% | EDGAR |
| SC 13G/A | 2001-01-10 | AMVESCAP PLC \GA\ | UNIT CORP | 0 | 0.0% | EDGAR |
| SC 13G/A | 2000-11-30 | WELLINGTON MANAGEMENT CO LLP | UNIT CORP | 335,000 | 0.9% | EDGAR |
| SC 13G/A | 2000-02-11 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 4,309,367 | 12.8% | EDGAR |
| SC 13G | 2000-02-11 | WELLINGTON MANAGEMENT CO LLP | UNIT CORP | 1,908,900 | 5.6% | EDGAR |
| SC 13G/A | 2000-02-11 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 4,309,367 | 12.8% | EDGAR |
| SC 13G | 2000-02-11 | WELLINGTON MANAGEMENT CO LLP | UNIT CORP | 1,908,900 | 5.6% | EDGAR |
| SC 13G | 2000-02-11 | WELLINGTON MANAGEMENT CO LLP | UNIT CORP | 1,908,900 | 5.6% | EDGAR |
| SC 13G/A | 2000-02-11 | FORSTMANN LEFF ASSOCIATES LLC | UNIT CORP | 4,309,367 | 12.8% | EDGAR |
| SC 13G | 2000-02-04 | AMVESCAP PLC \GA\ | UNIT CORP | 1,789,400 | 5.3% | EDGAR |