Perhaps you should try some spelling variations:
hieu cao » chieu cao, hieu ca, kieu cao
hieu cac » hieu luc, hieu va, hieu van
chat soc » cham soc, chat hoc, chat doc
danh dau » lanh dao, hang dau, danh tu
tu sach » thu sach, su sach, te sach
ky lang » ky dang, ky tang, tay lang
va danh » va dinh, va dan, va hanh
dau hoa » dau khoa, cau hoa, dai hoa
soc va » hoc va, loc va, doc va

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 ((ky lang) or (ky nang)) xa hoi. ((hieu cao) OR (hieu cac)) chat soc va danh dau hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky nang)) xa hoi. ((hieu cao) OR (hieu cac)) chat soc va danh dau hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) or (ky nang)) xa hoi. ((hieu cao) OR (hieu cac)) chat soc va danh dau hoa viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky nang)) xa hoi. ((hieu cao) OR (hieu cac)) chat soc va danh dau hoa viet*.