Perhaps you should try some spelling variations:
van khanh » van thanh, van hanh, van anh
hieu vien » hieu hien, hieu viec, thieu nien
khanh thi » nhanh thi, khanh thu, nhanh thai
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
vien da » vien dai, hien dai
xuc van » duc van, luc van, vuc van
cu tren » tu tren, dua tren
thi cu » thi cuc
o hoi » co hoi, o hoc, o hoa
o hai » co hai, so hai, o lai

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 ty nang ((o hoi) or (o hai)). hieu vien da xuc van khanh thi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((o hoi) OR (o hai)). hieu vien da xuc van khanh thi cu tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((o hoi) or (o hai)). hieu vien da xuc van khanh thi cu tren*.