Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
nang co » nang cao, nang doc, nang noi
hieu vi » hieu voi, hieu va, hieu ve
hang di » hang doi, hang vi, hang dien
co hoi » co hoc, co loi
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: ((thu sach) OR (tu sach)) ky nang co hoi. hieu vi pham thuc vat ((hanh vi) or (hang di)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky nang co hoi. hieu vi pham thuc vat ((hanh vi) OR (hang di)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (tu sach)) ky nang co hoi. hieu vi pham thuc vat ((hanh vi) or (hang di)) cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (tu sach)) ky nang co hoi. hieu vi pham thuc vat ((hanh vi) or (hang di)) cua te*.