Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
hanh ve » hanh vi, hanh va, hanh kem
hanh de » hanh kem
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
sach lo » sach dao, sach doi, sach hoi
nang ma » tang ma, sang ma, nang cao
lo nang » ho nang, ly nang, loai nang
ma hoi » mai hoi, xa hoi, ma hoa

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 sach lo nang ma hoi. ((hieu quan) OR (hieu qua)) nam thuc va ((hanh de) OR (hanh ve)) cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach lo nang ma hoi. ((hieu quan) or (hieu qua)) nam thuc va ((hanh de) OR (hanh ve)) cua viet~".
• Adding a wildcard symbol may retrieve word variants: tu sach lo nang ma hoi. ((hieu quan) or (hieu qua)) nam thuc va ((hanh de) OR (hanh ve)) cua viet*.