Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, sach thu
cuc ban » cua ban, cac ban, cuu ban
luc ban » duc ban, luc bat, luc van
so sach » so sanh, bo sach, co sach
hieu va » hieu qua
hang xa » hoang xa, hang va, hang ca
ty hang » ly hang, ty xang, thi hang
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 hang xa hoi. ((lieu va) or (hieu va)) cau ((luc ban) OR (cuc ban)) hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty hang xa hoi. ((lieu va) OR (hieu va)) cau ((luc ban) OR (cuc ban)) hanh vi cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty hang xa hoi. ((lieu va) or (hieu va)) cau ((luc ban) OR (cuc ban)) hanh vi cau tren*".