Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cua triet, dua tren
van anh » van thanh, tuan anh, van minh
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cuu tre » cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa
anh vi » hanh vi, anh va, anh ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (thuat sach)) ky tang ma hoi. hieu van cac duc van anh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuat sach)) ky tang ma hoi. hieu van cac duc van anh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thuat sach)) ky tang ma hoi. hieu van cac duc van anh vi ((cua tre) or (cuu tre))*.