Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh than » hanh han, hanh nhan, hanh phan
nang phap » nang phat, nang phan, ban phap
nang cai » nang cao, nang tai, nang cap
than cua » nhan cua, thai cua, ban cua
bach ky » bac ky
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ky ((nang cai) or (nang phap)) hoi. hieu va cam ((luc va) OR (tuc va)) hanh than cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky ((nang cai) OR (nang phap)) hoi. hieu va cam ((luc va) OR (tuc va)) hanh than cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ky ((nang cai) or (nang phap)) hoi. hieu va cam ((luc va) OR (tuc va)) hanh than cua triet".
• Adding a wildcard symbol may retrieve word variants: vu bach ky ((nang cai) or (nang phap)) hoi. hieu va cam ((luc va) OR (tuc va)) hanh than cua triet*.