Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
hanh hai » nhanh hai, hang hai, hanh tai
co sach » bo sach, cuon sach, hoc sach
van cam » van nam, van lam, van cau
cam cua » ca cua, nam cua, cau cua
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky danh
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ((ky dang) or (ky nang)) xay hoi. hieu van cam cua ban ((hanh hai) OR (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((ky dang) OR (ky nang)) xay hoi. hieu van cam cua ban ((hanh hai) OR (thanh hai)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((ky dang) or (ky nang)) xay hoi. hieu van cam cua ban ((hanh hai) OR (thanh hai)) cua tre*".