Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
van hang » van khang, van hoang, van thang
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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 (van xay)) hoi. hieu van cam xuc ((van hanh) or (van hang)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang xa) OR (van xay)) hoi. hieu van cam xuc ((van hanh) OR (van hang)) di cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang xa) or (van xay)) hoi. hieu van cam xuc ((van hanh) or (van hang)) di cua tre*.