const year: number = 2018; const author: string = 'Woehrer Zdun'; const title: string = 'Smart Contracts: Security Patterns in the Ethereum Ecosystem and Solidity'; const literature : string = `${year} - ${author} - ${title}`; console.log(literature.toLocaleLowerCase('de-DE').replace(/[ ]+/g, '_').replace(/[.:]+/, ''));