Off-topic, but anyone knows where to buy such [1] old but not rare (so they are cheap enough) math books? In UK and globally? Is e-bay and perhaps amazon the be

Off-topic, but anyone knows where to buy such [1] old but not rare (so they are cheap enough) math books? In UK and globally? Is e-bay and perhaps amazon the best place? How to avoid fakes? [1] https://www.lostartoflogarithms.com/chapter01/ https://www.lostartoflogarithms.com/chapter01/