Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh lai » hanh lam, hanh tai, thanh lap
tham duc » pham duc, tham du, than duc
van tham » van thanh, van tuan, van chat
hieu van » hieu va, thien van, lieu va
lai cuu » lai cua, lai chau, lai cuoc
va hanh » van hanh, va thanh, va danh
cao hoi » cau hoi, co hoi, cao hoc
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ((ty nang) or (ty hang)) cao hoi. hieu van tham duc va hanh lai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((ty nang) OR (ty hang)) cao hoi. hieu van tham duc va hanh lai cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ((ty nang) or (ty hang)) cao hoi. hieu van tham duc va hanh lai cuu tre*.