求助啊，关于申请research fellow需要的材料一个朋友推荐我去申请国大的research fellow，写信过去，人家回信要这些东西，俺菜鸟一个，想请各位前辈指点 1. Duly completed Personal Particular Form , which is attached 2. Brief CV (resume) including a list of publications 3. Copies of three best research publications, 4. Three reference letters (preferably academic), 5. Statement of research interests and goals, including the reason for participation in this program, 6. Copies of relevant degrees duly certified by a public notary, and 7. A photocopy of passport and NRIC 其中第4条推荐信有什么要求，各位有经验的请指点一二，谢谢！