Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
cua triet » su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
danh dai » danh dau, danh di, danh sai
cua viet » ca viet, hoa viet, cua vat
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
cac dac » cac dan, cac dai, cac bac
va danh » va dinh, va dan, va hanh
dac va » duc va, day va, dat va

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 thue ((nang xa) OR (nang x)) hoi. hieu va cac dac va danh dai ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thue ((nang xa) OR (nang x)) hoi. hieu va cac dac va danh dai ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thue ((nang xa) OR (nang x)) hoi. hieu va cac dac va danh dai ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: toc sach thue ((nang xa) OR (nang x)) hoi. hieu va cac dac va danh dai ((cua triet) or (cua viet))*.