Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
chat soc » cham soc, chat hoc, chat song
chat doc » chat hoc, chau doc, thuat doc
hanh dau » hang dau, danh dau, han dau
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
dau cua » dai cua, day cua, cau cua
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 ky nang x hoi. hieu van ((chat soc) or (chat doc)) va hanh dau cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu van ((chat soc) OR (chat doc)) va hanh dau cua viet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu van ((chat soc) or (chat doc)) va hanh dau cua viet*.