Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ta_ lang » tai lang, tay lang, tham lang
hieu van » hieu va, thien van, lieu va
nam xuc » cam xuc, nam xua, nam thuc
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
va cua » va chua, via cua, ca 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 ((_ lang) or (ta_ lang)) xa hoi. hieu van nam xuc va danh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((_ lang) OR (ta_ lang)) xa hoi. hieu van nam xuc va danh va cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((_ lang) or (ta_ lang)) xa hoi. hieu van nam xuc va danh va cua tre*.