Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, lieu vien
toc sach » doc sach, thuoc sach, nuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
hoc sach » hoc sinh, hoc cac, hoc anh
nang co » nang cao, nang doc, nang noi
ty nang » ky nang, ty xang, ty hang
cac duc » cac du, cao duc, cac nuoc
cac dac » cac dan, cac dai, cac bac
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 (hoc sach)) ty nang co hoc. hieu vien ((cac duc) or (cac dac)) van hanh dai cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ty nang co hoc. hieu vien ((cac duc) OR (cac dac)) van hanh dai cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ty nang co hoc. hieu vien ((cac duc) or (cac dac)) van hanh dai cua cau*".