Perhaps you should try some spelling variations:
hang viet » hoang viet, nang viet, mang viet
cau tren » cu tren, dau tren, ca tren
viet cau » viet chau, viet ca, viet chu
luc ngan » luc nganh, luc nhan, luat ngan
dang xay » dang van, van xay
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
lang xa » lang ha, lang van
ve cau » ke cau, va cau, le cau
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((lang xa) or (dang xay)) hoi. hieu ((ve cau) OR (ve cac)) luc ngan hang viet cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((lang xa) OR (dang xay)) hoi. hieu ((ve cau) OR (ve cac)) luc ngan hang viet cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((lang xa) or (dang xay)) hoi. hieu ((ve cau) OR (ve cac)) luc ngan hang viet cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((lang xa) or (dang xay)) hoi. hieu ((ve cau) OR (ve cac)) luc ngan hang viet cau tren*.