Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((nang ma) or (nang x)) hoi. hieu va cam tuc va hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((nang ma) OR (nang x)) hoi. hieu va cam tuc va hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((nang ma) or (nang x)) hoi. hieu va cam tuc va hanh hai cua tre*.