Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
hoc hanh » hoc nhanh, hoc thanh, hoc anh
hanh dai » hanh tai, hanh dao, vanh dai
ky lang » ky dang, ky tang, tay lang
van hoi » van hoa, van hoc, van hoe
cac duc » cao duc, cac dac, cac nuoc
va hanh » van hanh, va thanh, va danh
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hanh ((ky lang) OR (ky nang)) van hoi. hieu viec ((cac duc) or (cac du)) va hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hanh ((ky lang) OR (ky nang)) van hoi. hieu viec ((cac duc) OR (cac du)) va hanh dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hanh ((ky lang) OR (ky nang)) van hoi. hieu viec ((cac duc) or (cac du)) va hanh dai cua te".
• Adding a wildcard symbol may retrieve word variants: hoc hanh ((ky lang) OR (ky nang)) van hoi. hieu viec ((cac duc) or (cac du)) va hanh dai cua te*.