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
tu sach » thu sach, su sach, te sach
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
cac xuc » cam xuc, cac nuoc, chat xuc
mai hoi » mai khoi, dai hoi, lai hoi
ky lang » ky dang, ky tang, tay lang
cuu tre » cua tre, cau tren, cau treo
xuc va » duc va, tuc va, luc va

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

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