Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » lieu va, hieu qua
cau luc » cau truc, cau phuc
luc va » duc va, tuc va, loc va
di cua » doi cua, de cua, do 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 ky nang xa hoi. ((hieu ve) or (hieu va)) cau luc va thanh ((di cua) OR (dai cua)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. ((hieu ve) OR (hieu va)) cau luc va thanh ((di cua) OR (dai cua)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. ((hieu ve) or (hieu va)) cau luc va thanh ((di cua) OR (dai cua)) tu".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. ((hieu ve) or (hieu va)) cau luc va thanh ((di cua) OR (dai cua)) tu*.