Man must be tireless in his effort. Once his effort is directed in the proper channel, if he does not succeed today he shall succeed tomorrow.
DAS.Diary notebooks and letters of Mirza Ahmad Sohrab, Dec. 1912 – Jun. 1915. English and Persian diary notebooks and letters held in the U.S. National Bahá’í Archives. Often quoted in other sources such as SW. Catalog entries are indexed by date and include only the English notebooks and letters. Letters from 1 Jul 1913 through 19 Oct. 1914 found here: https://bahai-library.com/sohrab_diary_letters_1913-1914
SW.Star of the West, 25 vols. (1910-1935). Periodical issued each Bahá’í month. Vols. 1-12 reprinted 1978 in 8 volumes by George Ronald. Each issue Includes a section in Persian. https://bahai.works/Star_of_the_West