Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
thanh va » thanh van, hanh va, thanh ha
cau tren » cu tren, dau tren, cau treo
thanh vi » hanh vi, thanh ve, nhanh vi
hieu va » lieu va, hieu qua
cao luc » bao luc, cao duc, cao suc
luc gia » luoc gia, duc gia, quoc gia
sach ty » sach y, sach tu, sach thu
xang ha » lang ha, tang ha, dang ha
ca tren » cu tren, la tren, co tren
va cao » va cac, va co, va dao
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ty xang ha hoi. hieu va cao luc gia ((thanh vi) or (thanh va)) ((cau tren) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty xang ha hoi. hieu va cao luc gia ((thanh vi) OR (thanh va)) ((cau tren) OR (ca tren)).
• Adding a wildcard symbol may retrieve word variants: doc sach ty xang ha hoi. hieu va cao luc gia ((thanh vi) or (thanh va)) ((cau tren) or (ca tren))*.