Perhaps you should try some spelling variations:
thanh vi » thanh va, thanh ve, nhanh vi
cac thuc » cach thuc, cac thu, can thuc
su sach » so sach
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
su viet » so viet
vu sach » vu bach, vu khach
xang o » lang o, tang o, dang o
ve cac » va cac, vien cac
o hoi » co hoi, o hoc, o hai

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) OR (vu sach)) ty xang o hoi. hieu ve cac thuc va ((thanh vi) or (hanh vi)) su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ty xang o hoi. hieu ve cac thuc va ((thanh vi) OR (hanh vi)) su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ty xang o hoi. hieu ve cac thuc va ((thanh vi) or (hanh vi)) su viet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ty xang o hoi. hieu ve cac thuc va ((thanh vi) or (hanh vi)) su viet*.