Perhaps you should try some spelling variations:
vuc nang » cuc nang, vu nang, chuc nang
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
ca truc » cau truc, ca tru, ba truc
hanh va » hang va, hanh vi
v nang » va nang, vu nang, van nang
ma hoi » mai hoi, xa hoi, ma hoa
qua ca » qua cac, qua cua, qua cai
va cua » va chua, via cua, ca cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((v nang) or (vuc nang)) ma hoi. hieu qua ca truc van hanh va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (vuc nang)) ma hoi. hieu qua ca truc van hanh va cua viet.
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (vuc nang)) ma hoi. hieu qua ca truc van hanh va cua viet*.