Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cau treo » cau theo, cau triet, cau trieu
cam thuc » am thuc, nam thuc, cam thu
sach ty » sach y, sach tu, sach thu
va dinh » van dinh, va kinh, va tinh
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
mang xa » lang xa, mang may, dang xay
ty mang » ty xang, ty hang, tin mang
va danh » va dan, va hanh, dia danh
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty mang xa hoi. hieu ve cam thuc ((va danh) or (va dinh)) tri ((cau treo) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty mang xa hoi. hieu ve cam thuc ((va danh) OR (va dinh)) tri ((cau treo) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty mang xa hoi. hieu ve cam thuc ((va danh) or (va dinh)) tri ((cau treo) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: su sach ty mang xa hoi. hieu ve cam thuc ((va danh) or (va dinh)) tri ((cau treo) OR (cau tren))*.