Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc day » thuc dan, thuc vat
cao hoi » co hoi, cao hoc, tao hoi
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan
luu tre » luu tru, cuu tre, luy tre
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
vi luu » vi lua

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