Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
va trien » va truyen, va thiet, va tuyen
sang mai » sang ma, sang tai, lang mai
qua nhat » qua hoat, luc nhat, qua hai
nhat tuc » nhat tu, nhat nuoc, luat tuc
va hanh » van hanh, va thanh, ban hanh
su sach » so sach, vu sach
va danh » va dinh, va dan, dia danh
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky sang mai hoi. hieu qua nhat tuc ((va danh) OR (va hanh)) vi ((cua triet) or (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang mai hoi. hieu qua nhat tuc ((va danh) OR (va hanh)) vi ((cua triet) OR (va trien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky sang mai hoi. hieu qua nhat tuc ((va danh) OR (va hanh)) vi ((cua triet) or (va trien))".
• Adding a wildcard symbol may retrieve word variants: su sach ky sang mai hoi. hieu qua nhat tuc ((va danh) OR (va hanh)) vi ((cua triet) or (va trien))*.