Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
gia phan » gia nhan, gia pha, gia thanh
phan lap » phan dau
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
van bac » van ban, van bao, van hac
duc gia » quoc gia
lap su » lap du, lap tu, lai su
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: ((su sach) or (((te sach) or (toc sach)))) ky nang x hoi. hieu van bac duc gia phan lap su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (((te sach) OR (toc sach)))) ky nang x hoi. hieu van bac duc gia phan lap su triet.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (((te sach) or (toc sach)))) ky nang x hoi. hieu van bac duc gia phan lap su triet*.