Perhaps you should try some spelling variations:
cach hoc » cach thuc, cach thoi, dich hoc
canh tay » canh tac, thanh tay, anh ta
cua tre » cua te, cuu tre, cua triet
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
va cach » va cac
anh tay » anh ta, anh hay, anh tai
hieu va » lieu va, hieu qua
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((anh tay) OR (canh tay)) hoi. hieu va cach hoc ((va hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((anh tay) OR (canh tay)) hoi. hieu va cach hoc ((va hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky ((anh tay) OR (canh tay)) hoi. hieu va cach hoc ((va hanh) or (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((anh tay) OR (canh tay)) hoi. hieu va cach hoc ((va hanh) or (va danh)) vi cua tre*.