Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van ban
cham duc » pham duc, pham duy, phan duc
su sach » so sach, vu sach
lam cua » nam cua, lam chat
van anh » van thanh, tuan anh, van minh
cua tre » cua te, cuu tre, cua triet
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
tu tang » tuc tang, tu trang, tu tong

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 tu tang ma hoa. hieu va ((cham duc) or (cham soc)) ((van hanh) OR (van anh)) lam cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu tang ma hoa. hieu va ((cham duc) OR (cham soc)) ((van hanh) OR (van anh)) lam cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu tang ma hoa. hieu va ((cham duc) or (cham soc)) ((van hanh) OR (van anh)) lam cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach tu tang ma hoa. hieu va ((cham duc) or (cham soc)) ((van hanh) OR (van anh)) lam cua tre*.