Perhaps you should try some spelling variations:
duoc tren » nuoc tren, thuoc tren, dung tren
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, sach tham
lang ha » long ha
sach ty » sach y, sach tu, xach tay
van lam » van nam
lam xuc » cam xuc, lam duoc
dao thi » do thi, dan thi, dang thi
duc tre » duc tien
ha hoi » hoa hoi, ha noi, xa hoi
xuc ca » xuc cam, xuc cua

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 ty) or (sach thu)) lang ha hoi. hieu van lam xuc ca dao thi ((duc tre) OR (duoc tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sach thu)) lang ha hoi. hieu van lam xuc ca dao thi ((duc tre) OR (duoc tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) or (sach thu)) lang ha hoi. hieu van lam xuc ca dao thi ((duc tre) OR (duoc tren))".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) or (sach thu)) lang ha hoi. hieu van lam xuc ca dao thi ((duc tre) OR (duoc tren))*.