Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hang dau » hang va, hang tai
thuc van » thuc vat, thuc dan, thuc va
cua viet » ca viet, hoa viet, cua vat
nang lai » nang tai, mang lai, nang cai
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
lai hoi » dai hoi, lai hoa, lai roi
tuc van » truc van, tuc va, duc van
y nang » ky nang, ly nang, v nang
cua te » cua tu

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 lai hoi. hieu ve cham ((tuc van) OR (thuc van)) hang dau ((cua te) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang lai hoi. hieu ve cham ((tuc van) OR (thuc van)) hang dau ((cua te) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang lai hoi. hieu ve cham ((tuc van) OR (thuc van)) hang dau ((cua te) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang lai hoi. hieu ve cham ((tuc van) OR (thuc van)) hang dau ((cua te) or (cua viet))*.