Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thanh vi » hanh vi, thanh va, thanh ve
te sach » toc sach
thi lan » thi hanh, thi nang, thi lien
hieu va » lieu va
luu tre » luu tru, cuu tre, luy tre
lan ha » lang ha, van ha, tan ha
ha hoi » hoa hoi, ha noi, xa hoi
tuc va » thuc va, truc va, tuc xa
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thi lan ha hoi. ((hieu va) OR (hieu qua)) cham ((tuc va) or (duc va)) thanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi lan ha hoi. ((hieu va) OR (hieu qua)) cham ((tuc va) OR (duc va)) thanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi lan ha hoi. ((hieu va) OR (hieu qua)) cham ((tuc va) or (duc va)) thanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: te sach thi lan ha hoi. ((hieu va) OR (hieu qua)) cham ((tuc va) or (duc va)) thanh vi luu tre*.