Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
su sach » so sach, vu sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
xuc va » tuc va, luc va, xac va
vi cua » vai cua, di cua

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

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