Perhaps you should try some spelling variations:
nang mai » nang tai, lang mai, nang cai
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
hanh ki » hanh vi, hanh ky, hanh kien
xuc van » duc van, luc van, vuc van
cao xuc » cam xuc, cao duc, cao suc
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
nang ma » tang ma, sang ma, nang cao
su viet » so viet
va cao » va cac, va co, va dao
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 mai) or (nang ma)) hoi. hieu va cao xuc van hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu ((nang mai) OR (nang ma)) hoi. hieu va cao xuc van hanh ki su viet.
• Adding a wildcard symbol may retrieve word variants: tu sach vu ((nang mai) or (nang ma)) hoi. hieu va cao xuc van hanh ki su viet*.