Some more tips for electronic versions:
Download the PDF or Kindle versions. The EPubs apparently use OCR, which is very error-prone and often loses the illustrations.
On archive.org some of the PDFs are listed as PDF (Google), which apparently means you can't download them, but rather have to read them online from Google by logging in, yada yada yada.
It may be beneficial to download both the PDF and the Kindle version, if your device supports both, as one or the other may result in a clearer copy. Check the quality and keep the best one.
Happy cheap reading.
