Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh lai » hanh lam, hanh tai, thanh lap
hieu van » hieu va, thien van, lieu va
ty hang » ly hang, ty xang, thi hang
van cac » van hac, van cau, van bac
ty nang » ky nang, ty xang, ly nang
lai cua » dai cua, hai cua, lai chau
cua te » cua tu
ac va » tac va, bac va, mac va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cac ((ac va) or (duc va)) hanh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cac ((ac va) OR (duc va)) hanh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cac ((ac va) or (duc va)) hanh lai cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cac ((ac va) or (duc va)) hanh lai cua te*.