Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, lieu vien
van hanh » van thanh, ban hanh, van ban
vien cac » vien bach, vien dai, vien da
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
ty nang » ky nang, ty xang, ty hang
nang co » nang cao, nang doc, nang noi
cac duc » cac du, cao duc, cac dac
van anh » van thanh, tuan anh, van minh
cua cau » cua cac, cua chu, cua cay

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (doc sach)) ty nang co hoc. hieu vien cac duc ((van hanh) or (van anh)) dai cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty nang co hoc. hieu vien cac duc ((van hanh) OR (van anh)) dai cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty nang co hoc. hieu vien cac duc ((van hanh) or (van anh)) dai cua cau*".