Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
thuc day » thuc dan, thuc vat
thuc cay » thuc can, thuc cao, thuc xay
su sach » so sach, vu sach
va tham » van tham, va cham, va thanh
cao hoi » cau hoi, co hoi, cao hoc
vu nang » vuc nang, va nang, vu dang
v nang » va nang, van nang, voi nang
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((v nang) OR (vu nang)) cao hoi. lieu va tham ((thuc cay) or (thuc day)) vanh dai cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (vu nang)) cao hoi. lieu va tham ((thuc cay) OR (thuc day)) vanh dai cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) OR (vu nang)) cao hoi. lieu va tham ((thuc cay) or (thuc day)) vanh dai cua su".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) OR (vu nang)) cao hoi. lieu va tham ((thuc cay) or (thuc day)) vanh dai cua su*.