Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cau treo » cau theo, cau tren, cau triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
nam xuc » cam xuc, nam xua, nam thuc
va kinh » qua kinh
sach ky » sac ky, sach y, sach ty
va tinh » may tinh
cuu tre » cua tre, cau tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky lang xa hoi. hieu van nam xuc ((va kinh) or (va tinh)) va ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu van nam xuc ((va kinh) OR (va tinh)) va ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. hieu van nam xuc ((va kinh) or (va tinh)) va ((cuu tre) OR (cau treo))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu van nam xuc ((va kinh) or (va tinh)) va ((cuu tre) OR (cau treo))*.