Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
doc sach » hoc sach, nuoc sach, dac sac
toc sach » hoc sach, thuoc sach, nuoc sach
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
hanh van » thanh van, khanh van, hanh va
cao hoi » cau hoi, co hoi, cao hoc
hieu vi » hieu voi, hieu va, hieu ve
su tien » su kien, su hien, tu tieng
van su » dan su

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) or (toc sach)) ky nang cao hoi. hieu vi pham thuc van hanh van su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (toc sach)) ky nang cao hoi. hieu vi pham thuc van hanh van su tien.
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (toc sach)) ky nang cao hoi. hieu vi pham thuc van hanh van su tien*.