Scratch 1 – http://myarduino.dk/Scratch/Scratch_2016_1.pdf 2 – http://myarduino.dk/Scratch/Scratch2_2014_1.pdf 3 – http://myarduino.dk/Scratch/Scratch3_2019_1.pdf 4 – http://myarduino.dk/Scratch/Scratch3-2019_2.pdf