Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
truc va » thuc va, thuc vat, trung va
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
tuc va » thuc va, tuc xa, duc va
vi cua » vai cua, di cua
ve cam » ve cham, ve cac, va cam

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: tu sach ky ((nang ma) OR (dang xay)) hoi. hieu ve cam ((tuc va) OR (truc va)) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) or (dang xay)) hoi. hieu ve cam ((tuc va) OR (truc va)) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (dang xay)) hoi. hieu ve cam ((tuc va) OR (truc va)) hanh vi cua tre*.