Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ve thanh » le thanh, de thanh, den thanh
su sach » so sach, vu sach
vu cham » va cham, vu kham, tu cham
ve cham » va cham, ve chat, ve chim
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cuu ve » cuu va
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 ty nang ((o hoi) OR (o hoc)). hieu ((ve cham) or (vu cham)) cuu ve thanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((o hoi) OR (o hoc)). hieu ((ve cham) OR (vu cham)) cuu ve thanh dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((o hoi) OR (o hoc)). hieu ((ve cham) or (vu cham)) cuu ve thanh dai cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ((o hoi) OR (o hoc)). hieu ((ve cham) or (vu cham)) cuu ve thanh dai cua te*.