Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang mai » dang hai, dang mau, dang bai
van hanh » van thanh, ban hanh, van anh
cac xuc » cam xuc, cac nuoc, chat xuc
lai cua » dai cua, lai chau, thai cua
hai cua » thai cua, dai cua, hoi cua
xuc van » duc van, luc van, vuc van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky dang » ky nang, ky danh

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 mai hoi. ((hieu ve) OR (hieu va)) cac xuc van hanh ((hai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang mai hoi. ((hieu ve) OR (hieu va)) cac xuc van hanh ((hai cua) OR (lai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang mai hoi. ((hieu ve) OR (hieu va)) cac xuc van hanh ((hai cua) or (lai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang mai hoi. ((hieu ve) OR (hieu va)) cac xuc van hanh ((hai cua) or (lai cua)) tre*.