Salmon cited several sources in Vie de Monseigneur Daveluy . In previous preface, he noted that the data from the Daveluy family was very helpful. On the other hand, it also referred to other sources. He also cited data from Bishop Ridel , Father Calais . and Féron , surviving missionaries, as well as data provided by M.E.P , including Histoire de l'Eglise de Corée by Dallet . Salmon quoted in a biography a letter from Daveluy to his family. In addition, this course focused on the general situation of Korea, the situation of Korean missionary field, the lifestyle of missionaries and pastoral visits, and the narrative of the church history of Daveluy . Through this, he reveals the public aspect as vice vicar apostolic of Korea and the missionary of Korean Church, while also expressing his personal relationship with the Catholic family. Salmon judged that the human appearance in his family relationships did not undermine Daveluy as a missionary. In addition, the figures of human beings in the process of the official mission of Daveluy were revealed in the letter. Salmon did not remain in the emphasis of the image of the good pastor and the expression of the glory of martyrdom. He sought to reveal the human aspect of Daveluy as a pastor. Indeed, Salmon expressed the joy and hope, the pain, and the anxiety of Daveluy , as a missionary, as well as the continual ties with his family. The most relevant source for that intention was a letter from his family. He sought to describe the biography as objectively as possible, based on what Daveluy wrote in the letter. Salmon 's quoting character is that he described a systematic biography by properly arranging the story of the public mission and private relationship in the letter.