Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
cao hoi » cau hoi, cao hoc, tao hoi
qua cam » qua cham, qua cac, qua ca
doi cua » dai cua, hoi cua, dong cua
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi

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 ty xang ((cao hoi) or (co hoi)). hieu qua cam xuc ((van hanh) or (van thanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang ((cao hoi) OR (co hoi)). hieu qua cam xuc ((van hanh) OR (van thanh)) doi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty xang ((cao hoi) or (co hoi)). hieu qua cam xuc ((van hanh) or (van thanh)) doi cua tre*.