At the beginning of 1973, Sava Popov was appointed by Svetlin Roussev, at that time deputy chairman of the Union of Bulgarian Artists (UBA), as a “literary associate” and “deputy managing secretary” of their informational bulletin. The two of them knew each other from the Literary Front newspaper, for which the then young Svetlin Roussev regularly drew illustrations. Sava Popov worked for the UBA for two years. There he coordinated the bulletin’s content and layout, and edited exhibition reviews, official speeches, and eulogies. He retired in 1974, when he was 60. That same year he prepared a new edition of Sly Peter.

In June 1974, the third edition of Sly Peter was published. The book was designed by Peter Chuhovski, with the idea of Iliya Beshkov’s drawings to attract a greater audience under the logo of the Bulgarian Artist Publishing House. The problems for the author began when the publishing house decided to change the original conditions and move the book into the category of “children’s picture books,” where the royalties for the authors of the text were minimal. In a letter to a close friend, Sava Popov wrote: “I will receive the money from the publishing house. It’s a lot of money. The matter will go to court. It might happen in two months or two years. But it will happen.”

On August 13, Sava Popov wrote a letter to the director of Bulgarian Artist publishers. In the letter, he pointed out the book’s good reception and the fact that the entire print run had been bought by the Knigorazprostranenie state distribution enterprise.  He thanked all the workers of the publishing house and shared his distress that this joy had not been shared with the author, “even as a formality,” and that a little attention had not been given at least “with a coffee or a glass of sparkling water and a few words.”

From a letter from Sava Popov to the Bulgarian Artist Publishing House, 1974

Comrade Director, if you are not playing some kind of wicked merchant’s prank like in one of the Sly Peter stories, then I am obliged to inform you at once that I absolutely do not agree with the application of item 40 of the tariff. You all from the publishing house, as well as every person in our country, know very well what kind and which books are according to the definition of item 40, “Picture books for children of preschool and primary school age, in which illustrations predominate.”

The book Sly Peter relates only to item 6 or item 15, with the resulting right to additional remuneration. As throughout the entire world, our legislator too has shown foresight (so as not to brook a “spirit of envy”) and granted the author the right and opportunity to receive a higher percentage of remuneration, the greater the circulation of the book.”

Sava Popov’s dispute with the Bulgarian Artist Publishing House was about whether Sly Peter was a picture book for children or a book for all ages. His royalties as an author depended on it. During the hearing, experts intervened – the literary specialists Elka Konstantinova and Ivan Sarandev and the artist Rumen Skorchev, who categorically proved that the book was not only for children.