There is also "The Art of Logical Thinking; Or, The Laws of Reasoning by William Walker Atkinson" https://gutenberg.org/ebooks/41838 at Gutenberg.org.
The Art of Logical Thinking is available in multiple formats, including ePub (my favorite), while The Art of Thinking by Dimnet seems to be only available as an HTML for online reading.
It has been many years since I read my paperback copy of this. Some memorable quotes:
> Don't read, study.
> Inspiration, the high-strung condition in which emotion, eloquence, music, or merely strong coffee can place us... reveals to us whole regions in our souls which have nothing in common with the sandy barrenness of our daily existence.
> Social intercourse ... is highly productive of thought-hindering insincerity.
> Some people who think freely and charmingly in speaking seem to put their minds in a straitjacket at the moment they begin to write.
The Art of Logical Thinking is available in multiple formats, including ePub (my favorite), while The Art of Thinking by Dimnet seems to be only available as an HTML for online reading.