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

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) OR (ve cac)) tuc 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) OR (ve cac)) tuc 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) OR (ve cac)) tuc va hanh vi cua tre*.