Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
cau treo » cau theo, cau tren, cau triet
dua tren » dung tren
hieu van » hieu va, thien van, lieu va
dinh vi » dinh ve, dinh viet, dinh tri
va dinh » van dinh, va kinh, va tinh
truc va » thuc va, thuc vat, trung va
bo sach » co sach, hoc sach
lang xa » lang ha, dang xay, lang van
bang xa » bang va, mang xa, ang xa
van cau » van dau, van hau, van chat

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach thien ((bang xa) or (lang xa)) hoi. hieu van cau truc va dinh vi ((dua tren) or (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach thien ((bang xa) OR (lang xa)) hoi. hieu van cau truc va dinh vi ((dua tren) OR (cau treo)).
• Adding a wildcard symbol may retrieve word variants: bo sach thien ((bang xa) or (lang xa)) hoi. hieu van cau truc va dinh vi ((dua tren) or (cau treo))*.