Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
va hanh » van hanh, va thanh, va danh
tu hang » thu hang, tu hanh, tu hung
hang x » nang x, hoang xa, chang xu
ve tai » te tai, de tai, le tai
va cao » va cac, va co, va dao
vi cua » vai cua, di cua
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (thu sach)) tu hang x hoi. hieu ((ve tai) or (va cao)) duc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu hang x hoi. hieu ((ve tai) OR (va cao)) duc va hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) tu hang x hoi. hieu ((ve tai) or (va cao)) duc va hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) tu hang x hoi. hieu ((ve tai) or (va cao)) duc va hanh vi cua te*.