Note 2 — APPENDIX II.
Reading edition
For a general view of the changes undergone in vowels since the tables of sounds were made, for example changes from u to ú, o to ia, chi to ch, sí to sz, ui to ei, ü to ú, é to í, á to ó, ó to á, etc. v. Grammar of Mandarin Dialect, ch. 8, § 5.