Perhaps you should try some spelling variations:
sach hoi » sach doi, sach moi, cach thoi
cau treo » cau theo, cau tren, cau triet
hieu van » hieu va, thien van, lieu va
xa hanh » xa thanh, xa khanh, va hanh
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
su sach » so sach, vu sach
lang ha » long ha
lang xa » dang xay, lang van
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: su sach hoi ((lang xa) OR (lang ha)) hoi. hieu van cac tuc xa hanh vi ((cau treo) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoi ((lang xa) OR (lang ha)) hoi. hieu van cac tuc xa hanh vi ((cau treo) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach hoi ((lang xa) OR (lang ha)) hoi. hieu van cac tuc xa hanh vi ((cau treo) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: su sach hoi ((lang xa) OR (lang ha)) hoi. hieu van cac tuc xa hanh vi ((cau treo) or (cua te))*.