I suggest 2 books on juice fasting: Dr. Michael T. Murray "The complete book of juicing!" There he also mentions Jay Kordich, who had cancer and who started a juice fast. He drank 13 glases of juices from carots mixed with apples a day, for the time of 2 1/2 years!!!!! He was completely healed.
Dr. Norman Walker´s book is called: "Fresh vegetable and fruit juices!" He wrote is last book with 113years old before he died 116 years young.
I sometimes fast with blue grapes only and it is also a wonderful fast, which can be done for weks and weeks.
Good luck to you from
Markus in germany