Perhaps you should try some spelling variations:
hai truc » dai truc, hai trac, hang truc
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
dang xa » dang xay, lang xa, dang ha
qua hai » qua hoat
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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: so ((sach ky) OR (sach ty)) dang xa hoi. hieu qua hai truc va hanh ((vi cua) OR (di cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ky) OR (sach ty)) dang xa hoi. hieu qua hai truc va hanh ((vi cua) or (di cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: so ((sach ky) OR (sach ty)) dang xa hoi. hieu qua hai truc va hanh ((vi cua) or (di cua)) triet*.