Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hoa lang » hoa dan, hoa van
te sach » toc sach
cac tac » cac toc, cac bac, cac dac
cac tuc » cac toc, cac tu, cac nuoc
cua tuc » cua duc, cua tu, cua thuoc
hieu ve » hieu va, hieu van
o lang » hoi lang
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((o lang) or (hoa lang)) xa hoi. hieu ve ((cac tuc) OR (cac tac)) van hanh vi cua tuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((o lang) OR (hoa lang)) xa hoi. hieu ve ((cac tuc) OR (cac tac)) van hanh vi cua tuc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((o lang) or (hoa lang)) xa hoi. hieu ve ((cac tuc) OR (cac tac)) van hanh vi cua tuc".
• Adding a wildcard symbol may retrieve word variants: te sach ((o lang) or (hoa lang)) xa hoi. hieu ve ((cac tuc) OR (cac tac)) van hanh vi cua tuc*.