Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
ban hanh » ban hang
vuc nang » cuc nang, chuc nang, van nang
hanh ki » hanh vi, hanh ky, hanh kien
xuc ban » duc ban, cuc ban, quoc ban
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
va nang » van nang, da nang, cam nang
vu nang » vu dang, v nang, vu bang
mai hoi » mai khoi, dai hoi, lai hoi
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: tu sach ((((vu nang) OR (va nang))) or (vuc nang)) mai hoi. hieu va cam xuc ban hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((((vu nang) OR (va nang))) OR (vuc nang)) mai hoi. hieu va cam xuc ban hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((((vu nang) OR (va nang))) or (vuc nang)) mai hoi. hieu va cam xuc ban hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((((vu nang) OR (va nang))) or (vuc nang)) mai hoi. hieu va cam xuc ban hanh ki su triet*.