Perhaps you should try some spelling variations:
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va thanh, va danh
cac luc » cau luc, coc luc, cac nuoc
hieu va » lieu va, hieu qua
te sach » toc sach
lang ha » long ha
nang xa » nang x, lang xa, nang ma
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: te sach ty ((nang xa) or (lang ha)) hoi. hieu va cac luc va hanh ((di cua) OR (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang xa) OR (lang ha)) hoi. hieu va cac luc va hanh ((di cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang xa) or (lang ha)) hoi. hieu va cac luc va hanh ((di cua) OR (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang xa) or (lang ha)) hoi. hieu va cac luc va hanh ((di cua) OR (dai cua)) tre*.