Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc anh
hieu van » hieu va, thien van, lieu va
hoc cac » hoc cao
ty lang » tay lang, ty hang, tu lang
van cam » van nam, van lam, van cau
cam luc » cam xuc, cau luc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
va cua » va chua, via cua, ca 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: ((hoc sach) OR (hoc cac)) ((ty lang) OR (ty xang)) xa hoi. hieu van cam luc va hanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) OR (hoc cac)) ((ty lang) or (ty xang)) xa hoi. hieu van cam luc va hanh va cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) OR (hoc cac)) ((ty lang) or (ty xang)) xa hoi. hieu van cam luc va hanh va cua tre*.