Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
mai khoi » mai khoa, tai khoa, cac khoi
mai hoi » dai hoi, lai hoi, mai hoa
mai doi » moi doi, mai duoc, mai tuoi
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
vu nang » vuc nang, va nang, vu dang
hanh ki » hanh vi, hanh ky, hanh kien
te sach » toc sach
va cam » va cham, va cac, va cao
ki su » ky su

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 vu nang ((((mai hoi) OR (mai doi))) or (mai khoi)). hieu va cam xuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach vu nang ((((mai hoi) OR (mai doi))) OR (mai khoi)). hieu va cam xuc van hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach vu nang ((((mai hoi) OR (mai doi))) or (mai khoi)). hieu va cam xuc van hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: te sach vu nang ((((mai hoi) OR (mai doi))) or (mai khoi)). hieu va cam xuc van hanh ki su triet*.