Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh duc » thach duc, than duc, thinh duc
hoang hai » hoang thi, hoang van
van nang » van quang, van ban, van dong
hieu ban » hieu van, dieu ban, lieu ban
hang hai » hang tai, thanh hai, hang va
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, voi nang

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 ((v nang) or (van nang)) mai hoi. hieu ban thanh duc va ((hang hai) OR (hoang hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (van nang)) mai hoi. hieu ban thanh duc va ((hang hai) OR (hoang hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) or (van nang)) mai hoi. hieu ban thanh duc va ((hang hai) OR (hoang hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (van nang)) mai hoi. hieu ban thanh duc va ((hang hai) OR (hoang hai)) cua tre*.