Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
cua triet » cua viet, su triet, va triet
thuc ban » thuoc ban, thuc dan, thu ban
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
hieu va » hieu qua
hanh va » hang va, hanh vi
va cua » va chua, via cua, ca cua
tu sac » tu cac, tu san, tu bac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu sach)) ky mang may hoi. ((hieu va) OR (lieu va)) nham thuc ban hanh va cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu sach)) ky mang may hoi. ((hieu va) OR (lieu va)) nham thuc ban hanh va cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) or (tu sach)) ky mang may hoi. ((hieu va) OR (lieu va)) nham thuc ban hanh va cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu sach)) ky mang may hoi. ((hieu va) OR (lieu va)) nham thuc ban hanh va cua triet*.