Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach
xuc van » duc van, luc van, vuc van
ve cham » va cham, ve chat, vu cham
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
vu sach » vu bach, vu khach
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
ve cam » ve cac, va cam, ve cai
vi cua » vai cua, di cua

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 (vu sach)) ky tang ma hoi. hieu ((ve cam) OR (ve cham)) xuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky tang ma hoi. hieu ((ve cam) OR (ve cham)) xuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky tang ma hoi. hieu ((ve cam) OR (ve cham)) xuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky tang ma hoi. hieu ((ve cam) OR (ve cham)) xuc van hanh vi cua tre*.