In the LWB of the Universal Wirth Tarot is mentioned that they use a book by Eudes Picard called "Manual synthetique et practique de Tarot" from 1909 to create the Minor Arcana.
In an article fromChristine Payne-Towler it is mentioned that the essay on the Minor Arcana by Eudes Picard, appears in "The Encyclopedia of Occult Sciences", which was published anonymously in English in 1939.
"The Encyclopedia of Occult Sciences" can be found as pdf on the internet e.g here
and on page 432ff there is Picards text on the Minor Arcana :)
Maybe others here would also like to download this to complete the not very detailed LWB from the Universal Wirth….