Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
dau xuc » dau xac, dau xua, dau nuoc
sach ly » sach y, sach lo, sach ty
van dau » van dao, phan dau
ly nang » ky nang, ly hang, ly vang
xuc va » duc va, tuc va, luc va
vi cua » vai cua
di cua » dai cua, doi cua, de cua
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 xuc va thanh ((vi cua) OR (di 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 xuc va thanh ((vi cua) OR (di 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 xuc va thanh ((vi cua) OR (di cua)) te".
• Adding a wildcard symbol may retrieve word variants: toc sach ly nang ((5 hoi) or (xa hoi)). hieu van dau xuc va thanh ((vi cua) OR (di cua)) te*.