Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
cac dac » cac dan, cac dai, cac bac
dao cua » day cua, dan cua, do cua
sach ty » sach y, sach tu, sach thu
cac duc » cac du, cao duc, cac nuoc
nang co » nang cao, nang doc, nang noi
ty nang » ky nang, ty xang, ty hang

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 ty nang co hoc. hieu viec ((cac duc) or (cac dac)) van hanh ((dao cua) OR (dai cua)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang co hoc. hieu viec ((cac duc) OR (cac dac)) van hanh ((dao cua) OR (dai cua)) cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang co hoc. hieu viec ((cac duc) or (cac dac)) van hanh ((dao cua) OR (dai cua)) cau*".