Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lang van » dang van, tang van, hoang van
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
lang xa » lang ha, dang xay
luu tre » luu tru, cuu tre, luy tre
xuc va » duc va, tuc va, luc va
vi luu » vi lua

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