Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
dau tren » dau tien, dat tren, dau tieng
ky dang » ky nang
ky danh » ky anh
van cam » van nam, van lam, van cau
van vat » van chat, nhan vat
cuu tre » cua tre, cau tren, cau treo
xuc va » duc va, tuc va, luc va

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 dang) or (ky danh)) xa hoi. hieu van cam xuc va van vat ((cuu tre) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky dang) OR (ky danh)) xa hoi. hieu van cam xuc va van vat ((cuu tre) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky dang) or (ky danh)) xa hoi. hieu van cam xuc va van vat ((cuu tre) or (dau tren))*.