Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cac quoc » cac nuoc, cao quoc, han quoc
cac cuoc » cac nuoc, ca cuoc, can cuoc
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
dai hoi » dai hoc, dai hai, dai moi
lai hoi » lai hoa, lai roi, mai hoi
ty nang » ky nang, ty xang, ty hang
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((lai hoi) OR (dai hoi)). hieu vien ((cac cuoc) OR (cac quoc)) va hanh vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((lai hoi) or (dai hoi)). hieu vien ((cac cuoc) OR (cac quoc)) va hanh vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ((lai hoi) or (dai hoi)). hieu vien ((cac cuoc) OR (cac quoc)) va hanh vi cua vat*.