Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va huong » va thuong, va phuong, va tuong
hieu va » lieu va, hieu qua
cach tu » cach thuc
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
doi cau » di cau, doi ca, doi cay
doi dau » doan dau

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 ky nang xa hoi. hieu va ((cach tu) or (cac du)) va huong ((doi cau) OR (doi dau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu va ((cach tu) OR (cac du)) va huong ((doi cau) OR (doi dau)) treo*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu va ((cach tu) or (cac du)) va huong ((doi cau) OR (doi dau)) treo*".