Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hang hai » hoang hai, hang tai, thanh hai
hanh hai » thanh hai, nhanh hai, hanh tai
duoc va » nuoc va, duc va, duoc ma
te duoc » te quoc, tao duoc
hieu ve » hieu va, hieu van
ky sang » ky dang, ky tang, duy sang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
ve te » le te, ve ke, ve tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ky sang) or (ky nang)) ma hoi. hieu ve te duoc va ((hanh hai) OR (hang hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky sang) OR (ky nang)) ma hoi. hieu ve te duoc va ((hanh hai) OR (hang hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky sang) or (ky nang)) ma hoi. hieu ve te duoc va ((hanh hai) OR (hang hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky sang) or (ky nang)) ma hoi. hieu ve te duoc va ((hanh hai) OR (hang hai)) cua tre*.