Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh vi » thanh va, thanh ve, nhanh vi
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
van cam » van nam, van lam, van cau
xuc van » duc van, luc van, xuc ban
cua tre » cua te, cuu tre, cua triet

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 ((nang xa) OR (nang x)) hoi. hieu van cam xuc van ((thanh vi) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang xa) OR (nang x)) hoi. hieu van cam xuc van ((thanh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((nang xa) OR (nang x)) hoi. hieu van cam xuc van ((thanh vi) or (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang xa) OR (nang x)) hoi. hieu van cam xuc van ((thanh vi) or (hanh vi)) cua tre*.