Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, ban hanh, van anh
noi cuu » noi cua, nhim cuu
va hanh » va thanh, va danh, ban hanh
dao loc » dao cuoc
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
va lang » va nang, hoa lang
o lang » hoa lang, hoi lang
va dao » ca dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((va lang) or (o lang)) xa hoi. hieu va dao loc ((va hanh) OR (van hanh)) noi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((va lang) OR (o lang)) xa hoi. hieu va dao loc ((va hanh) OR (van hanh)) noi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((va lang) or (o lang)) xa hoi. hieu va dao loc ((va hanh) OR (van hanh)) noi cuu tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((va lang) or (o lang)) xa hoi. hieu va dao loc ((va hanh) OR (van hanh)) noi cuu tre*.