Perhaps you should try some spelling variations:
sieu viet » su viet, dien viet, bien viet
suu viet » su viet, sau viet, so viet
hanh dao » lanh dao, thanh dat, thanh dam
co trach » bo trach, co tranh, co tich
hieu va » lieu va, hieu qua
co truc » co thuc, cau truc, hoc truc
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
te sach » toc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky dang xa hoi. hieu va ((co truc) or (co trach)) va hanh dao ((suu viet) OR (sieu viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang xa hoi. hieu va ((co truc) OR (co trach)) va hanh dao ((suu viet) OR (sieu viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang xa hoi. hieu va ((co truc) or (co trach)) va hanh dao ((suu viet) OR (sieu viet))".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang xa hoi. hieu va ((co truc) or (co trach)) va hanh dao ((suu viet) OR (sieu viet))*.