Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
vai cua » dai cua, hai cua, lai cua
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va, hieu van
cua tu » cua tuc, cua su, cua cu
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

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