Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cac thu » cach thuc, cac thoi
hang xa » hoang xa, hang ca, lang xa
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
vi cua » vai cua, di cua
cua te » cua tu
ca thu » cam thu, ca tru, va thu

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

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