Perhaps you should try some spelling variations:
luc tieng » hoc tieng
tu tieng » tu tuong, tu trong
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach y, sach lo, sach ty
te sach » toc sach
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
ma hoi » mai hoi, xa hoi, ma hoa
dau vi » dau ve, dau va, dat vi

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: te sach ly nang ma hoi. hieu vu cham ((duc va) OR (thuc va)) dau vi ((tu tieng) OR (luc tieng))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly nang ma hoi. hieu vu cham ((duc va) or (thuc va)) dau vi ((tu tieng) OR (luc tieng))~".
• Adding a wildcard symbol may retrieve word variants: te sach ly nang ma hoi. hieu vu cham ((duc va) or (thuc va)) dau vi ((tu tieng) OR (luc tieng))*.