Perhaps you should try some spelling variations:
tran tuan » tran xuan, tran quang, tran thanh
thong tan » thong than, thong tran, thong tin
chi sach » chinh sach, chieu sach, co sach
tran van » luan van
doi chi » doi khi
tan ran » tan tran, tan van, tan san
ran cau » van cau, ban cau, can cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doi chi sach - hanh ((tran tuan) or (tran van)) thong thong tan ran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chi sach - hanh ((tran tuan) OR (tran van)) thong thong tan ran cau.
• Adding a wildcard symbol may retrieve word variants: doi chi sach - hanh ((tran tuan) or (tran van)) thong thong tan ran cau*.