question about EB1A: the date of recom letters

Need help from experts:
Got support letters from my references dated October, 2006. The letters were meant for Outstanding Researchers (it specifically stated xxx is an outstanding researchers etc).
I didn't get to EB1B for some reasons.
Now I am preparing for EB1A. Can these letters be used for the EB1A petition? Do I have to ask them to write new letters?

Thank you very much. I really appreciate the help.

所有跟帖： 

• 回复：question about EB1A: the date of recom letters -llp1- ♀ (408 bytes) () 03/03/2007 postreply 16:21:33

• no experience. but i think the letter is still good -hengheng1- ♂ (0 bytes) () 03/06/2007 postreply 20:32:08

• 回复：非常感谢! -llp1- ♀ (0 bytes) () 03/07/2007 postreply 19:30:10