Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cam thuc » am thuc, nam thuc, cam thu
cau treo » cau theo, cau triet, cau trieu
danh hai » dang hai, lanh hai, manh hai
hieu van » hieu va, thien van, lieu va
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
so sach » so sanh, bo sach, co sach
hang xa » hoang xa, hang va, hang ca
ly hang » ly quang
vu sach » vu bach, su sach, vu khach
van cam » van nam, van lam, van 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) or (vu sach)) ly hang xa hoi. hieu van cam thuc va danh hai ((cau treo) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (vu sach)) ly hang xa hoi. hieu van cam thuc va danh hai ((cau treo) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (vu sach)) ly hang xa hoi. hieu van cam thuc va danh hai ((cau treo) or (cau tren))*.