This could eventually play out as the mother of all "three fan principles" E&M, 5th edition, pages 257-259.
Shown on right in picture is from original 1948 printing, leather bound from John Magee's library
Editions past #6 have been altered not to be trusted
Reference to a technical analysis pattern ('three fan principles') from a 1948 edition of an E&M textbook, with a warning that editions past #6 have been altered and shouldn't be trusted.
关键要点
Mentions 'three fan principles' from E&M 5th edition (pages 257-259)
References original 1948 printing from John Magee's library
Claims editions after #6 have been altered and are not trustworthy