Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cam truc » nam truc, lam truoc, nam truoc
cau treo » cau theo, cau triet, cau trieu
dan hai » doan hai, dang hai, dan khai
sach ly » sach y, sach lo, sach ty
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
va dan » ca dan, va dao, va dau
ma hoi » mai hoi, xa hoi, ma hoa

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 ly nang ma hoi. hieu va ((cam truc) OR (cau truc)) va dan hai ((cau treo) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ly nang ma hoi. hieu va ((cam truc) OR (cau truc)) va dan hai ((cau treo) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ly nang ma hoi. hieu va ((cam truc) OR (cau truc)) va dan hai ((cau treo) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: so sach ly nang ma hoi. hieu va ((cam truc) OR (cau truc)) va dan hai ((cau treo) or (cau tren))*.