Perhaps you should try some spelling variations:
tu sach » thu sach, te sach, tu cach
lang ha » long ha
hieu va » lieu va, hieu qua
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, xa hoi
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
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: ((tu sach) or (su sach)) ky lang ha hoi. hieu va cac ((xuc va) OR (tuc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky lang ha hoi. hieu va cac ((xuc va) OR (tuc va)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky lang ha hoi. hieu va cac ((xuc va) OR (tuc va)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky lang ha hoi. hieu va cac ((xuc va) OR (tuc va)) hanh vi cua tre*.