Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, lang xa, nang ma
qua cau » quan cau, qua cac, qua ca
cau luc » cau truc, cau phuc
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
y nang » ky nang, ly nang, v nang
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu cua

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