Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh van » trinh van, dinh van, tinh va
va tham » van tham, va thanh, va thuat
van cua » vang cua, ban cua, dan cua
va tinh » may tinh
va cham » va chat
ly nang » ly hang, ly vang, ly quang
cua su » qua su
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: toc sach ((ly nang) or (ky nang)) o hoi. hieu ((va cham) OR (va tham)) duc va tinh van cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ly nang) OR (ky nang)) o hoi. hieu ((va cham) OR (va tham)) duc va tinh van cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ly nang) or (ky nang)) o hoi. hieu ((va cham) OR (va tham)) duc va tinh van cua su".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ly nang) or (ky nang)) o hoi. hieu ((va cham) OR (va tham)) duc va tinh van cua su*.