Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
va cua » va chua, via cua, ca cua
x hoi » xa hoi, o hoi, x ho
ve am » va am

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cac) or (((te sach) OR (toc sach)))) ky nang x hoi. hieu ve am thuc va danh va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cac) OR (((te sach) OR (toc sach)))) ky nang x hoi. hieu ve am thuc va danh va cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cac) or (((te sach) OR (toc sach)))) ky nang x hoi. hieu ve am thuc va danh va cua viet*".