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

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 va hanh van ((su tien) OR (su hien))~.
• 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 va hanh van ((su tien) OR (su hien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) or (toc sach)) ky nang cao hoi. hieu vi pham thuc va hanh van ((su tien) OR (su hien))".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (toc sach)) ky nang cao hoi. hieu vi pham thuc va hanh van ((su tien) OR (su hien))*.