EXHIBIT A The undersigned, Ziff Asset Management, L.P., a Delaware limited partnership, PBK Holdings, Inc., a Delaware corporation, Philip B. Korsant, and ZBI Equities, L.L.C., a Delaware limited liability company, hereby agree and acknowledge that...Schedule 13g Filing Agreement • February 6th, 2006 • Ziff Asset Management Lp • Bituminous coal & lignite surface mining
The undersigned, Ziff Asset Management, L.P., a Delaware limited partnership, PBK Holdings, Inc., a Delaware corporation, Philip B. Korsant, and ZBI Equities, L.L.C., a Delaware limited liability company, hereby agree and acknowledge that the information required by this Schedule 13G, to which this Agreement is attached as an exhibit, is filed on behalf of each of them. The undersigned further agree that any further amendments or supplements thereto shall also be filed on behalf of each of them.
