Perhaps you should try some spelling variations:
dien viet » tieng viet, trien viet, gian viet
hanh dao » lanh dao, thanh dat, thanh dam
dao dien » dao tien, dat dien, do dien
ky dang » ky nang, ky danh
dang ma » dang mau, dang mam, dang mat
co thuc » do thuc, co thua, mo thuc
va hanh » van hanh, va thanh, va danh
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
co tuc » co tu, co toc, do tuc

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky dang ma hoa. hieu qua ((co tuc) or (co thuc)) va hanh dao dien viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky dang ma hoa. hieu qua ((co tuc) OR (co thuc)) va hanh dao dien viet.
• Adding a wildcard symbol may retrieve word variants: su sac ky dang ma hoa. hieu qua ((co tuc) or (co thuc)) va hanh dao dien viet*.