Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, gian cac
duc minh » duc anh
tu sach » thu sach, su sach, te sach
vien da » vien dai, hien dai
minh cu » minh cau, dinh cu, minh tu
cu tren » tu tren, dua tren
y nang » ky nang, ly nang, v nang
ve cac » va cac
va duc » van duc, va duoc, va doc
x hoi » xa hoi, o hoi, x ho
su va » su van, tu 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 y nang x hoi. hieu ((ve cac) or (((vien cac) or (vien da)))) su va duc minh cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu ((ve cac) OR (((vien cac) OR (vien da)))) su va duc minh cu tren.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu ((ve cac) or (((vien cac) or (vien da)))) su va duc minh cu tren*.