Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tang van » dang van, hoang van, trong van
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
thanh vi » hanh vi, thanh va, thanh ve
hieu va » lieu va, hieu qua
cac lap » cac lop, cac cap, cac tap
su viet » so viet
lap va » tap va
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y ((nang x) or (tang van)) hoi. ((hieu van) OR (hieu va)) cac lap va thanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang x) OR (tang van)) hoi. ((hieu van) OR (hieu va)) cac lap va thanh vi su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y ((nang x) or (tang van)) hoi. ((hieu van) OR (hieu va)) cac lap va thanh vi su viet*".