There are some outstanding books on the subject including The Smiling Pope: The Life And Teaching Of John Paul I by Raymond Seabeck and Lauretta Seabeck & In God's Name: An Investigation Into the Murder of Pope John Paul I by David Yallop
The first stage of the cause for beatification of Pope John Paul I will be concluded in November, according to the vice-postulator for that cause.
Msgr. Giorgio Lise told Vatican Radio that an investigation in the Venice archdiocese is nearing its conclusion, and the results will be forwarded to the Vatican in the autumn, for further study by the Congregation for the Causes of Saints. Witnesses regarding the life of Pope John Paul I have been heard in Rome and in Vittorio Veneto as well as Venice.
Cardinal Albino Luciani was the Bishop of Vittorio Veneto and then Patriarch of Venice before he was elected as Sovereign Pontiff in 1978. He died after less than a month as Pope. Then anniversary of his papal election will be observed in Rome on August 26.
Source: Catholic World News