Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dat hang » dat khanh, dat quang, tat thang
day hang » dai hang, day nang, dai thang
nam thuc » nam thuoc, am thuc, nam thu
hieu he » hieu ve, hiem he, hieu le
nang xa » nang x, lang xa, nang ma
co sach » bo sach, cuon sach, hoc sach
cuu tre » cua tre, cau tren, cau treo
he nam » ha nam, nghe nam
di cuu » di cau, di cua, dinh cuu

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) or (co sach)) ky nang xa hoi. hieu he nam thuc ((day hang) or (dat hang)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (co sach)) ky nang xa hoi. hieu he nam thuc ((day hang) OR (dat hang)) di cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (co sach)) ky nang xa hoi. hieu he nam thuc ((day hang) or (dat hang)) di cuu tre*.