Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
cua tre » cua te, cuu tre, cua triet
hanh di » hanh vi, hanh de, hang di
thuc va » thuc vat, thuc dan, thuc day
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
mai hoi » dai hoi, lai hoi, mai doi
ky tang » ky nang, ky dang, kho tang
sac ky » cac ky, sai ky
tuc va » truc va, tuc xa, duc va
di cua » dai cua, doi cua, de cua
vu sac » vu sach, vu san, va sac

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky tang ((mai hoi) or (mai khoi)). hieu ve cham ((tuc va) OR (thuc va)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky tang ((mai hoi) OR (mai khoi)). hieu ve cham ((tuc va) OR (thuc va)) hanh di cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sac ky tang ((mai hoi) or (mai khoi)). hieu ve cham ((tuc va) OR (thuc va)) hanh di cua tre*".