and cultural references. Some characters are parodies of well-known characters: for example, Pratchett's character Cohen the Barbarian, also called Ghengiz Cohen, is a parody of Conan the Barbarian and Genghis Khan, and his character Leonard of Quirm is a parody of Leonardo da Vinci. Another hallmark of his writing was the use of dialogue in small capitals without quotation marks, used to indicate the character of Death communicating telepathically into a character's mind. Other characters or types of characters were given similarly distinctive ways of speaking, such as the auditors of reality not having quotation marks around the words they speak, Ankh-Morpork grocers never using punctuation correctly, and Golems capitalising each word in their speech. Also, common spelling mistakes were used to indicate a person's level of literacy. Discworld novels often included a modern innovation and its introduction to the world's medieval setting, such as a public police force (Guards! Guards!), guns (Men at Arms), submarines (Jingo), cinema (Moving Pictures), investigative journalism (The Truth), the postage stamp (Going Postal), modern banking (Making Money), and the steam engine (Raising Steam). The "clacks", the tower-to-tower semaphore system that sprang up in later novels, is a mechanical optical telegraph (as created by the Chappe brothers and employed during the French revolution) before wired electric telegraph chains, with all the change and turmoil that such an advancement implies. The resulting social upheaval driven by these changes serves as the setting for the main story. Influences Pratchett made no secret of outside influences on his work: they were a major source of his humour. He imported numerous characters from classic literature, popular culture and ancient history, always adding an unexpected twist. Pratchett was a crime novel fan, which was reflected in frequent appearances of the Ankh-Morpork City Watch in the Discworld series. Pratchett was an only child, and his characters are often without siblings. Pratchett explained, "In fiction, only-children are the interesting ones". Pratchett's earliest inspirations were The Wind in the Willows by Kenneth Grahame, and the works of H. G. Wells, Isaac Asimov and Arthur C. Clarke. His literary influences were P.G. Wodehouse, Tom Sharpe, Jerome K. Jerome, Roy Lewis, Alan Coren, G. K. Chesterton, and Mark Twain. Publishing history While Pratchett's UK publishing history remained quite stable, his relationships with international publishers were turbulent (especially in America). He changed German publishers after an advertisement for Maggi soup appeared in the middle of the