Perhaps you should try some spelling variations:
than quoc » han quoc, tran quoc, toan quoc
hang tai » hang va, dung tai
hang hai » hoang hai, thanh hai, hang va
qua than » qua thanh, qua phan, qua tan
thanh vi » hanh vi, thanh va, thanh ve
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
vi su » va su, ve su, ki su
gia » giao

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((hang hai) or (hang tai)) hoi. hieu qua than quoc gia thanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((hang hai) OR (hang tai)) hoi. hieu qua than quoc gia thanh vi su triet.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((hang hai) or (hang tai)) hoi. hieu qua than quoc gia thanh vi su triet*.