Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
luat tuc » luat thue
dang xay » dang van, van xay
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
va luat » va thuat, vay luan, cua luat
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de cua

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

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