Perhaps you should try some spelling variations:
dang xay » dang van, van xay
ban mach » ban sach, ranh mach, ban hanh
mach hai » manh hai, mach phan, mach vi
su triet » su viet, su tien, ve triet
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky dang xay hoi. hieu ve pham duc ban mach hai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky dang xay hoi. hieu ve pham duc ban mach hai ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: vu sach ky dang xay hoi. hieu ve pham duc ban mach hai ((cua tre) or (su triet))*.