William Barclay Squire, Abel, Karl Friedrich, Dictionary of National Biography, 1885–1900, ”He returned to London in 1785, and occasionally played at concerts until his death, which took place, hastened by his habits of intemperance, June 20, 1787.”.[källa från Wikidata]
unknown value, Абель, Карл Фридрих, Brockhaus och Efrons encyklopediska lexikon, band I 1890.[källa från Wikidata]
