Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau luc » cau truc, cau phuc
nang xa » nang x, lang xa, mang xa
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
di cua » dai cua, doi cua, de cua
luc va » duc va, tuc va, loc va
ve cau » ke cau, va cau, ve cac
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty ((nang xa) OR (nang ma)) hoi. hieu ve cau luc va hanh di cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ty ((nang xa) OR (nang ma)) hoi. hieu ve cau luc va hanh di cua te~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty ((nang xa) OR (nang ma)) hoi. hieu ve cau luc va hanh di cua te*.