Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tu sach » thu sach, su sach, te sach
cua tre » cua te, cua triet, dua tren
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
hieu va » lieu va, hieu qua
cuu tre » cau tren, cau treo
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
xuc va » duc va, tuc va, luc va
va cam » va cham, va cac, va cao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (toc sach)) ky lang xa hoi. hieu va cam xuc va danh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky lang xa hoi. hieu va cam xuc va danh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky lang xa hoi. hieu va cam xuc va danh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky lang xa hoi. hieu va cam xuc va danh vi ((cua tre) OR (cuu tre))*.