Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
luoc van » luoc can, luoc va, luc van
nang doc » nang luc
bao luoc » bao luc, bao goc, bao hoc
viec bao » viec ban, viec lam, viec va
tai cuu » tai cuc, tai buu, tai cua
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang co » nang noi, nang hoc
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((((nang co) OR (nang cao))) or (nang doc)) hoi. hieu viec bao luoc van hanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((((nang co) OR (nang cao))) OR (nang doc)) hoi. hieu viec bao luoc van hanh tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((((nang co) OR (nang cao))) or (nang doc)) hoi. hieu viec bao luoc van hanh tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((((nang co) OR (nang cao))) or (nang doc)) hoi. hieu viec bao luoc van hanh tai cuu tre*.