Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
thai cua » than cua, tai cuc, tri cua
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu va » lieu va, hieu qua
cam tuc » cam xuc, nam thuc, dam thuc
sach ky » sac ky, sach y, sach ty
tai cua » tai cuc, tri cua, dai cua
va danh » va dinh, va dan, va hanh
cam tu » cam thu, nam tu, dam tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky dang xay hoi. hieu va ((cam tuc) OR (cam tu)) va danh ((tai cua) or (thai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xay hoi. hieu va ((cam tuc) OR (cam tu)) va danh ((tai cua) OR (thai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. hieu va ((cam tuc) OR (cam tu)) va danh ((tai cua) or (thai cua)) te".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. hieu va ((cam tuc) OR (cam tu)) va danh ((tai cua) or (thai cua)) te*.