Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
hoc sach » hoc sinh, hoc cac, hoc anh
hieu vi » hieu voi, hieu va, hieu ve
thuc va » thuc vat, thuc dan
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
ma hoi » mai hoi, xa hoi, ma hoa

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

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