Just found today that one book is done and another underway! Haven't listened yet— it's a slow connection (always is, per my experience) and I'm currently still downloading— so I can't vouch for the quality yet. Sed, jen!
Dr. Esperanto’s International Language, Introduction and Complete Grammar by L.L. Zamenhof
The Esperanto Teacher by Helen Fryer (in progress)
Darcy Ross on Local Groups Haroldo de Esperanto on NASK
Esperanto: Learning and Using the International Language.By David Richardson.
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