Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan
sach ky » sach y, sach ty, sach kem
hanh de » hanh ve, hanh kem
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
nang co » nang cao, nang doc, nang noi
sac ky » cac ky, sai ky
de cua » le cua, te cua, dieu cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) OR (sac ky)) nang co hoc. hieu ve pham ((thuc dan) or (thuc vat)) hanh de cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang co hoc. hieu ve pham ((thuc dan) OR (thuc vat)) hanh de cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sac ky)) nang co hoc. hieu ve pham ((thuc dan) or (thuc vat)) hanh de cua tu".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sac ky)) nang co hoc. hieu ve pham ((thuc dan) or (thuc vat)) hanh de cua tu*.