Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » vu sach
cua tre » cua te, cua triet, dua tren
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
so sach » so sanh, bo sach, co sach
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (so sach)) ky tang xa hoi. hieu va cac duc van hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky tang xa hoi. hieu va cac duc van hanh vi ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ky tang xa hoi. hieu va cac duc van hanh vi ((cua tre) or (cuu tre))*".