Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cam » vien cac, vien cao, vien nam
ty nang » ky nang, ty xang, ty hang
sach ty » sach y, sach tu, sach thu
cam luc » cam xuc, cau luc
va hanh » van hanh, va thanh, va danh
vai cua » hai cua, lai cua, bai cua
tu sach » thu sach, su sach, te sach
luc va » duc va, tuc va, loc va
o hoi » co hoi, o hoc, o hai

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 (xa hoi)). hieu vien cam luc va hanh ((vai cua) or (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((o hoi) OR (xa hoi)). hieu vien cam luc va hanh ((vai cua) OR (dai cua)) triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((o hoi) or (xa hoi)). hieu vien cam luc va hanh ((vai cua) or (dai cua)) triet*.