Perhaps you should try some spelling variations:
phap thuc » phap thu, phap hoc, phap tu
thu sach » tu sach, thuat sach, thuoc sach
hieu van » thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
di cua » dai cua, doi cua, de cua
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 ky nang cao hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) phap thuc dan hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang cao hoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) phap thuc dan hanh di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang cao hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) phap thuc dan hanh di cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang cao hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) phap thuc dan hanh di cua te*.