Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
lang xa » lang ha, dang xay, lang van
y lang » o lang, _ lang, tay lang
cam tu » cam thu, dam tu, tam tu
nam tu » nam thu, nam thuc
vi cuu » vi luu, vinh cuu

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