Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
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: ((tu sach) or (su sach)) ky sang ma hoa. hieu ve cac tuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky sang ma hoa. hieu ve cac tuc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky sang ma hoa. hieu ve cac tuc van hanh vi cua tre*.