Perhaps you should try some spelling variations:
dang xay » dang van, van xay
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, dai cua
va cam » va cham, va cac, va cao
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 ky ((nang x) OR (dang xay)) hoi. hieu va cam tuc va hanh ((tai cua) OR (tri cua)) te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (dang xay)) hoi. hieu va cam tuc va hanh ((tai cua) OR (tri cua)) te~".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (dang xay)) hoi. hieu va cam tuc va hanh ((tai cua) OR (tri cua)) te*.