Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
vai cuu » vai cua
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu va » hieu qua
sach ky » sac ky, sach y, sach ty
may hoi » may thoi, tay hoi, mai hoi
cuu tre » cua tre, cau tren, cau treo
sai ky » sac ky

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 ky) or (sai ky)) mang may hoi. ((hieu va) OR (lieu va)) cac duc van hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sai ky)) mang may hoi. ((hieu va) OR (lieu va)) cac duc van hanh vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sai ky)) mang may hoi. ((hieu va) OR (lieu va)) cac duc van hanh vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sai ky)) mang may hoi. ((hieu va) OR (lieu va)) cac duc van hanh vai cuu tre*.