Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hieu cua » hieu qua, dieu cua, bieu cua
cua luat » quy luat
luat tuc » luat thue
cau treo » cau theo, cau tren, cau triet
nang xa » nang x, lang xa, nang ma
doi cau » doi dau, di cau, doi ca

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) OR (hoc sach)) ky nang xa hoi. hieu cua luat tuc ((va tinh) or (may tinh)) doi cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky nang xa hoi. hieu cua luat tuc ((va tinh) OR (may tinh)) doi cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ky nang xa hoi. hieu cua luat tuc ((va tinh) or (may tinh)) doi cau treo".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) ky nang xa hoi. hieu cua luat tuc ((va tinh) or (may tinh)) doi cau treo*.