Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
dua tren » dung tren
thu sach » tu sach, thuat sach, thuoc sach
cac xuc » cam xuc, cac nuoc, chat xuc
su sach » so sach, vu sach
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cuu tre » cua tre, cau tren, cau treo
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (thu sach)) ky tang xa hoi. hieu vien cac xuc va dan vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) ky tang xa hoi. hieu vien cac xuc va dan vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) ky tang xa hoi. hieu vien cac xuc va dan vi ((dua tren) or (cuu tre))*.