Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
bao thuc » cao thuoc, am thuc, va thuc
cua viet » ca viet, cua vat, cua dieu
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
va bao » va bai

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 v nang xa hoi. lieu va bao thuc va danh di ((cua tre) or (((cua viet) OR (hoa viet))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang xa hoi. lieu va bao thuc va danh di ((cua tre) OR (((cua viet) OR (hoa viet)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang xa hoi. lieu va bao thuc va danh di ((cua tre) or (((cua viet) OR (hoa viet))))".
• Adding a wildcard symbol may retrieve word variants: toc sach v nang xa hoi. lieu va bao thuc va danh di ((cua tre) or (((cua viet) OR (hoa viet))))*.