Today's pony book is an iconic European pony book, one of the few which was translated into English. German author Ursula Bruns was just one of a whole mass of German pony book authors, who sadly remain mostly untranslated into English.
Snow Ponies, originally published as Dick und Dally und der Ponys, is a charming read of feisty children and Icelandic ponies. Author Ursula Bruns is widely credited with saving the Icelandic pony from extinction, after she imported a herd to Germany.
You can read more about Ursula Bruns here, as well as see pictures of her pony books.
Read more about the pony book in Heroines on Horseback, my survey of the world of the pony book from the 1930s onwards. You can buy a signed copy from me (I'll post them worldwide). The book's also available from the usual sources, or your local bookshop.