Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
toc sach » hoc sach, doc sach, thuoc sach
cac xuc » cac nuoc, chat xuc, cac cuoc
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
vi cua » vai cua, di cua
cua su » qua su

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) OR (toc sach)) tu nang xa hoi. hieu ve ((cac xuc) or (cam xuc)) van hanh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu nang xa hoi. hieu ve ((cac xuc) OR (cam xuc)) van hanh vi cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) tu nang xa hoi. hieu ve ((cac xuc) or (cam xuc)) van hanh vi cua su".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) tu nang xa hoi. hieu ve ((cac xuc) or (cam xuc)) van hanh vi cua su*.