Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
lieu van » lieu va, hieu van, sieu van
van pham » san pham, van phan, van phat
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
duc van » duc va, duc tan, duc manh
nang o » nang co, nang ho, nang ro
tai su » tai so, tai tu, lai su
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: ((thu sach) or (su sach)) ky nang o hoi. lieu van pham duc van hanh tai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ky nang o hoi. lieu van pham duc van hanh tai su triet.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ky nang o hoi. lieu van pham duc van hanh tai su triet*.