Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau tren » dau tren, ca tren, cau treo
luc ngan » luc nganh, luc nhan, luat ngan
sach ty » sach y, sach tu, sach thu
hang vi » hang va, hanh vi, hang di
cu tren » tu tren, dua tren
xang xa » lang xa, mang xa, ang xa
ve cau » va cau, ve cac, le cau
ke cau » ket cau

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

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