Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thu sach » tu sach, thuat sach, thuoc sach
vien cac » vien bach, vien dai, vien da
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
cac xuc » cam xuc, cac nuoc, chat xuc
va danh » va dinh, va dan, va hanh
doi cua » hoi cua
xuc va » duc va, tuc va, luc 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: thu sach ((ky tang) OR (ky dang)) xa hoi. hieu vien cac xuc va danh ((doi cua) OR (dai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky tang) or (ky dang)) xa hoi. hieu vien cac xuc va danh ((doi cua) OR (dai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky tang) or (ky dang)) xa hoi. hieu vien cac xuc va danh ((doi cua) OR (dai cua)) tre*.