Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((lang xa) OR (nang x)) hoi. hieu va cam ((xuc va) OR (tuc va)) thanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((lang xa) or (nang x)) hoi. hieu va cam ((xuc va) OR (tuc va)) thanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((lang xa) or (nang x)) hoi. hieu va cam ((xuc va) OR (tuc va)) thanh dai cua tre*.