Perhaps you should try some spelling variations:
hieu sau » hieu suat, tieu su, hieu va
doan dau » doan dieu, phan dau, doan va
thuc day » thuc dan, thuc vat
dau cua » dai cua, day cua, cau cua
te sach » toc sach
hieu su » tieu su, hieu so, hieu suat
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
tuc va » thuc va, truc va, tuc xa
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ma hoi. ((hieu su) OR (hieu sau)) kham ((tuc va) or (thuc day)) doan dau cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ma hoi. ((hieu su) OR (hieu sau)) kham ((tuc va) OR (thuc day)) doan dau cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ma hoi. ((hieu su) OR (hieu sau)) kham ((tuc va) or (thuc day)) doan dau cua te".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoi. ((hieu su) OR (hieu sau)) kham ((tuc va) or (thuc day)) doan dau cua te*.