A couple of free books (at the time of posting) about Nikola Tesla. And if they're rubbish, well they're free so just delete them
https://www.amazon.co.uk/dp/B075MH3N2M
https://www.amazon.co.uk/Nikola-Tesla-Imagination-Invented-Century-ebook/dp/B00CATSONE/ref=pd_sim_351_3?_encoding=UTF8&pd_rd_i=B00CATSONE&pd_rd_r=d7b1cc4a-8081-11e8-915b-ad4d0e8dff36&pd_rd_w=5BPEY&pd_rd_wg=70pv6&pf_rd_i=desktop-dp-sims&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=3274180622111699416&pf_rd_r=6GAM0JY073T45BH3Y1S2&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=6GAM0JY073T45BH3Y1S2