Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cau treo » cau theo, cau tren, cau triet
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
den vai » den va, den vay, den vi
dan tai » van tai, dan thi, han tai
va nam » van nam, ha nam, va nay

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 va nam thuc va ((den vai) or (dan tai)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu va nam thuc va ((den vai) OR (dan tai)) cau treo.
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu va nam thuc va ((den vai) or (dan tai)) cau treo*.