Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thanh vai » thanh hai, thanh van, thanh tai
cua triet » cua viet, su triet
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
nam duc » nam duoc, pham duc, nam thuc

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 xa hoi. hieu van nam duc tan thanh vai ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van nam duc tan thanh vai ((cua triet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van nam duc tan thanh vai ((cua triet) or (va triet))*.