Perhaps you should try some spelling variations:
manh hai » lanh hai, minh hai, thanh hai
danh hai » dang hai, lanh hai, danh hau
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
hieu he » hieu ve, hiem he, hieu le
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
thu xa » thu xac, thu ha, thu xe
sai ky » sac ky
he nam » ha nam, nghe nam

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 ky) or (sai ky)) nang ma hoi. hieu he nam thu xa ((danh hai) OR (manh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sai ky)) nang ma hoi. hieu he nam thu xa ((danh hai) OR (manh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sai ky)) nang ma hoi. hieu he nam thu xa ((danh hai) OR (manh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sai ky)) nang ma hoi. hieu he nam thu xa ((danh hai) OR (manh hai)) cua tre*.