Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
tinh via » tinh gia, tinh va, tinh vi
via cua » gia cua, gian cua, giau cua
tu nang » tru nang, tu nong, tu nano
va tinh » may tinh
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
cua te » cua tu
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) tu nang ((x hoi) OR (o hoi)). hieu van cam duc va tinh via cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu nang ((x hoi) OR (o hoi)). hieu van cam duc va tinh via cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) tu nang ((x hoi) OR (o hoi)). hieu van cam duc va tinh via cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) tu nang ((x hoi) OR (o hoi)). hieu van cam duc va tinh via cua te*.