Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
vuc nang » cuc nang, chuc nang, van nang
van hanh » van thanh, ban hanh, van anh
hanh ki » hanh vi, hanh ky, hanh kien
xuc van » duc van, luc van, vuc van
hieu va » lieu va, hieu qua
tu sach » thu sach, te sach, tu cach
vu nang » va nang, vu dang, v nang
su sach » so sach, vu sach
ma hoi » mai hoi, xa hoi, ma hoa
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.

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