Pieri (2015), p. 61: "In 2014, there was yet another change in TJ’s leadership with the passing away of Zubair ul-Hasan. Zubair was seen as the senior leader in the movement and teacher of the current leader Maulana Saad. ... Reetz commented that even before Maulana Zubair’s death, Maulana Saad moved to the center of the movement and was seen as the “spiritual and symbolic head” attracting immense popularity on an international level." Pieri, Zacharias P. (2015), Tablighi Jamaat and the Quest for the London Mega Mosque: Continuity and Change, Springer, ISBN978-1-137-46439-2