Perhaps you should try some spelling variations:
manh hai » lanh hai, minh hai, thanh hai
sach hay » sach han, sach ha, sach nay
sach tay » xach tay, sach nay, sach tai
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
dang xa » dang xay, lang xa, dang ha
ve cam » ve cham, ve cac, va cam
xac va » tac va, ac va, bac va

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 tay) OR (sach hay)) dang xa hoi. hieu ve cam ((xac va) or (duc va)) manh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach tay) OR (sach hay)) dang xa hoi. hieu ve cam ((xac va) OR (duc va)) manh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach tay) OR (sach hay)) dang xa hoi. hieu ve cam ((xac va) or (duc va)) manh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach tay) OR (sach hay)) dang xa hoi. hieu ve cam ((xac va) or (duc va)) manh hai cua tre*.