Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
hieu van » hieu va, thien van, lieu va
hanh di » hanh vi, hanh de, hang di
nang co » nang cao, nang doc, nang noi
hieu ve » hieu va
sach ky » sac ky, sach ty, sach kem
di cua » dai cua, doi cua, de cua
cua te » cua tu
co hoi » co hoc, co loi

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 y)) nang co hoi. ((hieu ve) OR (hieu van)) pham thuc day hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang co hoi. ((hieu ve) OR (hieu van)) pham thuc day hanh di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach y)) nang co hoi. ((hieu ve) OR (hieu van)) pham thuc day hanh di cua te".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang co hoi. ((hieu ve) OR (hieu van)) pham thuc day hanh di cua te*.