Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
dua tren » dung tren
thanh vi » hanh vi, thanh va, thanh ve
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
hieu ve » hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang

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 ky tang xa hoi. ((hieu ve) OR (hieu va)) cam duc van thanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky tang xa hoi. ((hieu ve) OR (hieu va)) cam duc van thanh vi ((dua tren) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky tang xa hoi. ((hieu ve) OR (hieu va)) cam duc van thanh vi ((dua tren) or (cuu tre))*".