Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
danh via » danh gia, danh va, danh viet
cua viet » ca viet, hoa viet, cua vat
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
via cua » gia cua, gian cua, giau cua
x hoi » o hoi, x ho, 5 hoi

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 ky nang ((x hoi) or (xa hoi)). ((hieu ve) or (hieu van)) am thuc va danh via cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ((x hoi) OR (xa hoi)). ((hieu ve) OR (hieu van)) am thuc va danh via cua viet.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ((x hoi) or (xa hoi)). ((hieu ve) or (hieu van)) am thuc va danh via cua viet*.