Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tru nang » tra nang, tri nang, truc nano
cac truc » cau truc, cac tru, cac trung
hanh tai » thanh tai, hang tai, han tai
va triet » va thiet, va trien, ve triet
tu nang » tu nong, tu nano, tu lang
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
tai va » thai va, mai va, tri va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((tu nang) or (tru nang)) xa hoi. lieu va cac truc va hanh tai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((tu nang) OR (tru nang)) xa hoi. lieu va cac truc va hanh tai va triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ((tu nang) or (tru nang)) xa hoi. lieu va cac truc va hanh tai va triet*.