Perhaps you should try some spelling variations:
vien canh » bien canh, vien can, vien nganh
canh thuc » anh thuc, cach thuc, danh thuc
trinh vat » trinh van, trinh luat, sinh vat
hieu vien » hieu hien, hieu viec, thieu nien
nang xay » dang xay, nganh xay, nang xuan
tinh va » tich va, trinh van, tinh gia
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach kem
xay hoi » xa hoi, tay hoi, cay phoi
sach ty » sach y, sach tu, sach thu
chu tre » cho tre, chu tri, cuu tre

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sach ty)) nang xay hoi. hieu vien canh thuc va ((tinh va) OR (trinh vat)) chu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang xay hoi. hieu vien canh thuc va ((tinh va) OR (trinh vat)) chu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach ty)) nang xay hoi. hieu vien canh thuc va ((tinh va) OR (trinh vat)) chu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang xay hoi. hieu vien canh thuc va ((tinh va) OR (trinh vat)) chu tre*.