Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
doc sac » doc sach, dac sac, hoc sach
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
cau luc » cau phuc
hanh ve » hanh vi, hanh va, hanh kem
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sac ky nang cao hoi. hieu va ((cau luc) or (cau truc)) van hanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sac ky nang cao hoi. hieu va ((cau luc) OR (cau truc)) van hanh ve cua tre.
• Adding a wildcard symbol may retrieve word variants: doc sac ky nang cao hoi. hieu va ((cau luc) or (cau truc)) van hanh ve cua tre*.