Perhaps you should try some spelling variations:
nhien cac » thien cac, vien cac, hieu cac
hanh dai » hanh tai, hanh dao, vanh dai
hien cac » thien cac, vien cac, hieu cac
toc sach » hoc sach, doc sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
sach ty » sach y, sach tu, sach thu
nang xa » lang xa, nang ma, mang xa
va hanh » van hanh, va thanh, va danh
xuc va » duc va, tuc va, luc 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 ty ((nang xa) or (nang x)) hoi. hien ((nhien cac) OR (hien cac)) xuc va hanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((nang xa) OR (nang x)) hoi. hien ((nhien cac) OR (hien cac)) xuc va hanh dai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty ((nang xa) or (nang x)) hoi. hien ((nhien cac) OR (hien cac)) xuc va hanh dai cua viet".
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((nang xa) or (nang x)) hoi. hien ((nhien cac) OR (hien cac)) xuc va hanh dai cua viet*.