Perhaps you should try some spelling variations:
lang dai » lang hai, lang mai, lang chai
quoc ban » quoc bao, quoc lan, quoc quan
thanh va » thanh van, hanh va, thanh ha
cua quoc » cua nuoc, cua thuoc
su sach » so sach, vu sach
dai hoi » dai hoc, dai hai, dai moi
hieu va » lieu va, hieu qua
xuc ban » duc ban, cuc ban, xuat ban
duc van » duc va, duc tan, duc manh
y lang » o lang, _ lang, tay lang
va cam » va cham, va cac, va cao
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: su sach y lang dai hoi. hieu va cam ((((xuc ban) OR (quoc ban))) or (duc van)) thanh va cua quoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y lang dai hoi. hieu va cam ((((xuc ban) OR (quoc ban))) OR (duc van)) thanh va cua quoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y lang dai hoi. hieu va cam ((((xuc ban) OR (quoc ban))) or (duc van)) thanh va cua quoc".
• Adding a wildcard symbol may retrieve word variants: su sach y lang dai hoi. hieu va cam ((((xuc ban) OR (quoc ban))) or (duc van)) thanh va cua quoc*.