Perhaps you should try some spelling variations:
manh hai » lanh hai, minh hai, thanh hai
banh hai » lanh hai, bang hai, benh hai
tu sach » thu sach, su sach, te sach
xuc ban » duc ban, cuc ban, quoc ban
qua cam » qua cham, qua cac, qua ca
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
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: tu sach ty ((nang x) or (nang ma)) hoi. hieu qua cam xuc ban ((banh hai) OR (manh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang x) OR (nang ma)) hoi. hieu qua cam xuc ban ((banh hai) OR (manh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang x) or (nang ma)) hoi. hieu qua cam xuc ban ((banh hai) OR (manh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang x) or (nang ma)) hoi. hieu qua cam xuc ban ((banh hai) OR (manh hai)) cua tre*.