Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cam tu » cam thu, nam tu, tam tu
dam tu » nam tu, tam tu, dam thuc
vi cua » vai cua, di cua
cua te » cua tu

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 y ((nang xa) or (nang cao)) hoi. hieu ve ((cam tu) OR (dam tu)) va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((nang xa) OR (nang cao)) hoi. hieu ve ((cam tu) OR (dam tu)) va hanh vi cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y ((nang xa) or (nang cao)) hoi. hieu ve ((cam tu) OR (dam tu)) va hanh vi cua te*".