Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tru nang » tra nang, tri nang, truc nano
hang tri » hang tai, lang tri, nang tri
va triet » va thiet, va trien, ve triet
tu nang » tu nong, tu nano, tu lang
cac tuc » cac toc, cac tu, cac tac
va hang » van hang, va nang, va lang
tuc va » thuc va, truc va, tuc xa

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 tuc va hang tri 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 tuc va hang tri va triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ((tu nang) or (tru nang)) xa hoi. lieu va cac tuc va hang tri va triet*.