Perhaps you should try some spelling variations:
hai truc » dai truc, hai trac, hang truc
hieu van » thien van, lieu va, hieu ve
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
hanh va » hang va, hanh vi
sang ma » tang ma, nang ma, sang tao
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
hieu va » lieu va, hieu qua
va cua » va chua, via cua, ca cua
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky

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

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