Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
lang xa » lang ha, lang van
van cac » van hac, van cau, van bac
cac duy » cac du, cac quy, cach dua
duy van » duy vat, dung van
vai cua » hai cua, lai cua, bai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach y ((lang xa) OR (dang xay)) hoi. hieu van cac duy van minh ((vai cua) or (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y ((lang xa) OR (dang xay)) hoi. hieu van cac duy van minh ((vai cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y ((lang xa) OR (dang xay)) hoi. hieu van cac duy van minh ((vai cua) or (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y ((lang xa) OR (dang xay)) hoi. hieu van cac duy van minh ((vai cua) or (dai cua)) te*.