Perhaps you should try some spelling variations:
cua quoc » cua nuoc, cua thuoc
thanh va » thanh van, hanh va, thanh ha
hieu van » hieu va, thien van, lieu va
lang dai » lang hai, lang mai, lang chai
dai hoi » dai hoc, dai hai, dai moi
van cam » van nam, van lam, van cau
xuc ban » duc ban, cuc ban, quoc ban
duc van » duc va, duc tan, duc manh
su sach » so sach, vu sach
tu sach » thu sach, te sach, tu cach
y lang » o lang, _ lang, tay lang
va cua » va chua, via cua, ca cua

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) OR (su sach)) y lang dai hoi. hieu van cam ((xuc ban) or (duc van)) thanh va cua quoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) y lang dai hoi. hieu van cam ((xuc ban) OR (duc van)) thanh va cua quoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) y lang dai hoi. hieu van cam ((xuc ban) or (duc van)) thanh va cua quoc".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) y lang dai hoi. hieu van cam ((xuc ban) or (duc van)) thanh va cua quoc*.