Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
dang xay » dang van
hieu cua » hieu qua, dieu cua, bieu cua
tu sach » thu sach, su sach, te sach
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
cac lop » cac hop, cac loai
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, lang van
lop va » lap va, hop va, nop va
cua tu » cua tuc, cua su, cua cu

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 ky ((lang xa) or (((dang xay) or (van xay)))) hoi. hieu cua cac lop va hanh hai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((lang xa) OR (((dang xay) OR (van xay)))) hoi. hieu cua cac lop va hanh hai cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((lang xa) or (((dang xay) or (van xay)))) hoi. hieu cua cac lop va hanh hai cua tu*.