Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
bach luc » bach tuoc, bach hue, bach qua
vai cuu » vai cua
va hanh » van hanh, va thanh, va danh
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky dang, ky tang, duy sang
cuu tre » cua tre, cau tren, cau treo
ma hoi » xa hoi, ma hoa, me hoi
luc va » duc va, tuc va, loc va

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: toc sach ((ky sang) OR (ky nang)) ((ma hoi) OR (mai hoi)). hieu vien bach luc va hanh vai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky sang) or (ky nang)) ((ma hoi) OR (mai hoi)). hieu vien bach luc va hanh vai cuu tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky sang) or (ky nang)) ((ma hoi) OR (mai hoi)). hieu vien bach luc va hanh vai cuu tre*.