Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » hieu va, thien van, lieu va
su sach » so sach
vu sach » vu bach, vu khach
tuc gia » tac gia, duc gia, toc gia
cam tuc » cam xuc, cam tu, nam thuc
van cam » van nam, van lam, van cau
cua te » cua tu
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (vu sach)) ky nang ((o hoi) OR (o hoc)). hieu van cam tuc gia thanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang ((o hoi) OR (o hoc)). hieu van cam tuc gia thanh dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky nang ((o hoi) OR (o hoc)). hieu van cam tuc gia thanh dai cua te".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky nang ((o hoi) OR (o hoc)). hieu van cam tuc gia thanh dai cua te*.