13-F/HR
- YORKTOWN ENERGY PARTNERS V LP - Bryan H. Lawrence
- Yorktown Energy Partners VI LP - Bryan H. Lawrence
- Yorktown Energy Partners VII, L.P. - Bryan H. Lawrence
- Yorktown Energy Partners VIII, L.P. - Bryan H. Lawrence
- Yorktown Energy Partners IX, L.P. - Bryan H. Lawrence
- Yorktown Energy Partners X, L.P. - Bryan H. Lawrence
- YT Extraction Co Investment Partners, LP - Bryan H. Lawrence
- Yorktown Energy Partners XI, L.P. - Bryan H. Lawrence