Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
dang xay » dang van, van xay
so sach » so sanh, bo sach, co sach
cao luc » bao luc, cao duc, cao suc
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va cao » va cac, va co, va dao
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: so sach ty ((nang xa) or (dang xay)) hoi. hieu va cao luc va thanh ((di cua) OR (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (dang xay)) hoi. hieu va cao luc va thanh ((di cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) or (dang xay)) hoi. hieu va cao luc va thanh ((di cua) OR (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) or (dang xay)) hoi. hieu va cao luc va thanh ((di cua) OR (dai cua)) te*.