Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
cao hoi » co hoi, cao hoc, tao hoi
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, luy tre
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang

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 y nang ((cao hoi) or (cau hoi)). hieu van cam thuc va hanh vi ((luu tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((cao hoi) OR (cau hoi)). hieu van cam thuc va hanh vi ((luu tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((cao hoi) or (cau hoi)). hieu van cam thuc va hanh vi ((luu tre) OR (cuu tre))*".