Perhaps you should try some spelling variations:
doanh vai » doanh tai, doanh van, doanh giai
cua triet » cua viet, su triet, va triet
doanh va » doan va, doanh tai, doanh cua
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
x hoi » xa hoi, o hoi, x ho
ve am » va am
thuc » thu

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. hieu ve am thuc vat ((doanh vai) or (doanh va)) ((cua triet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ve am thuc vat ((doanh vai) OR (doanh va)) ((cua triet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ve am thuc vat ((doanh vai) or (doanh va)) ((cua triet) or (cua vat))*.