Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach y, sach lo, sach ty
van dau » van dao, phan dau
ly nang » ky nang, ly hang, ly vang
tuc va » truc va, tuc xa, duc va
vi cua » vai cua, di cua
cua te » cua tu
5 hoi » o hoi

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 ly nang ((5 hoi) or (xa hoi)). hieu van dau ((tuc va) OR (thuc va)) thanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ly nang ((5 hoi) OR (xa hoi)). hieu van dau ((tuc va) OR (thuc va)) thanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ly nang ((5 hoi) or (xa hoi)). hieu van dau ((tuc va) OR (thuc va)) thanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ly nang ((5 hoi) or (xa hoi)). hieu van dau ((tuc va) OR (thuc va)) thanh vi cua te*.