Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
lang ha » long ha
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
cua tuc » cua tu, cua thuoc, luat tuc
cua duc » cua nuoc, cua quoc
ha hoi » hoa hoi, ha noi, xa hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach _ lang ha hoi. hieu va cac truc ((va hanh) OR (van hanh)) vi ((cua tuc) OR (cua duc))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach _ lang ha hoi. hieu va cac truc ((va hanh) or (van hanh)) vi ((cua tuc) OR (cua duc))~".
• Adding a wildcard symbol may retrieve word variants: te sach _ lang ha hoi. hieu va cac truc ((va hanh) or (van hanh)) vi ((cua tuc) OR (cua duc))*.