Perhaps you should try some spelling variations:
nang dai » nang dau, nang tai, lang dai
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
vu nang » vuc nang, va nang, vu dang
dai hoi » dai hoc, dai hai, dai moi
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
hanh ki » hanh vi, hanh ky, hanh kien
su viet » so viet
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) or (su sach)) vu nang dai hoi. hieu va cam xuc van hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) vu nang dai hoi. hieu va cam xuc van hanh ki su viet*.