Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
van thanh » van tuan
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
lang ha » long ha
nang xa » nang x, lang xa, nang ma
hieu vu » hieu va, hieu ve, hieu su
vu cam » vu cham, vu cao, va cam
vi cau » va cau, ve cau, di cau

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 (lang ha)) hoi. hieu vu cam xuc ((van thanh) OR (ban thanh)) vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (lang ha)) hoi. hieu vu cam xuc ((van thanh) OR (ban thanh)) vi cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) or (lang ha)) hoi. hieu vu cam xuc ((van thanh) OR (ban thanh)) vi cau tren*".