Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
thai cua » than cua, tai cuc, dai cua
sach ky » sac ky, sach ty, sach kem
nang ho » nang hoc, nang co, tang ho
qua cac » cua cac
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
ho hoi » hoc hoi, hoa hoi, hoi hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) or (sach y)) nang ho hoi. hieu qua cac duc van hanh ((thai cua) OR (tri cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang ho hoi. hieu qua cac duc van hanh ((thai cua) OR (tri cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) or (sach y)) nang ho hoi. hieu qua cac duc van hanh ((thai cua) OR (tri cua)) tre*".