https://frankgahl.com/books/ monthly 0.90 https://frankgahl.com/books/beyond_the_memory_hole/ monthly 0.80 https://frankgahl.com/books/blockclaim/ monthly 0.80 https://frankgahl.com/books/transferrecord/ monthly 0.80 https://frankgahl.com/books/witnessledger/ monthly 0.80