Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
tan hanh » tan thanh, tang hanh, toan hanh
hanh tai » thanh tai, hang tai, han tai
va triet » va thiet, va trien, ve triet
sach tu » cach tu, sach ty, sach uu
cham so » cham soc, cham o, ham so
so tan » so than, so toan, so tay
tai va » thai va, mai va, tri va
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach tu) or (sach thu)) nang x hoi. hieu van cham so tan hanh tai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach thu)) nang x hoi. hieu van cham so tan hanh tai va triet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) or (sach thu)) nang x hoi. hieu van cham so tan hanh tai va triet*.