Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
cua viet » ca viet, hoa viet, cua vat
nong cao » nang cao, cong cao, dong cao
nung cao » nang cao, nhung cau, quang cao
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
su sach » so sach
vu sach » vu bach, vu khach

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (vu sach)) tu ((nong cao) OR (nung cao)) hoi. hieu van cac duc ban thanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) tu ((nong cao) OR (nung cao)) hoi. hieu van cac duc ban thanh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) tu ((nong cao) OR (nung cao)) hoi. hieu van cac duc ban thanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) tu ((nong cao) OR (nung cao)) hoi. hieu van cac duc ban thanh vai cua viet*.