Perhaps you should try some spelling variations:
dat tren » dat trong, dua tren
hanh vai » hanh vi, hanh va, hanh tai
cam truc » cau truc, nam truc, lam truoc
hieu van » hieu va, thien van, lieu va
sang ma » tang ma, sang tao, mang may
vai dat » cai dat, va dat, van dat
nang ma » tang ma, nang cao, mang may
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va
truc va » thuc va, thuc vat, trung va
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((sang ma) OR (nang ma)) hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai dat tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu can ky ((sang ma) or (nang ma)) hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai dat tren~".
• Adding a wildcard symbol may retrieve word variants: tu can ky ((sang ma) or (nang ma)) hoi. ((hieu ve) OR (hieu van)) cam truc va hanh vai dat tren*.