Perhaps you should try some spelling variations:
sau viet » su viet, dau viet, sau biet
suu viet » su viet, sieu viet, so viet
hanh dao » lanh dao, thanh dat, thanh dam
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
cac tru » ca tru, cac tro, cac tu
hieu va » lieu va, hieu qua
may hoi » may thoi, tay hoi, mai hoi
ky mang » ky nang, ke mang, ky dang
cac thu » cach thuc, cac thoi

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

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