Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
van cam » van nam, van lam, van cau
sach ky » sac ky, sach y, sach ty
truc va » thuc va, thuc vat, trung va
dan vat » dang vat, van vat, dan va
cuu tre » cua tre, cau treo
tuc va » thuc va, tuc xa, duc 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 xa hoi. hieu van cam ((tuc va) or (truc va)) dan vat ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xa hoi. hieu van cam ((tuc va) OR (truc va)) dan vat ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xa hoi. hieu van cam ((tuc va) or (truc va)) dan vat ((cuu tre) or (cau tren))*.