Why was Nicholas II overthrown? How had Russia changed in this era to cause the end of the monarchy?

Why was Nicholas II overthrown? How had Russia changed in this era to cause the end of the monarchy?
Paper should be done in APA using citations. Only use the following sources to cite your paper (You are not allowed to use any other references for this paper):
Ferro, M. (1993). Nicholas II: Last of the tsars. New York: Oxford University Press.
Firsov, S. L. (2012). Emperor Nicholas II as an Orthodox Tsar. Russian Studies In History, 50(4), 79-90.
Massie, R. K. (1998, Jul 20). The wrong man for the time. Newsweek, 132, 34.
Shakibi, Z. (2007). Revolutions and the collapse of monarchy: Human agency and the making of revolution in France, Russia, and Iran. London: I.B. Tauris.
Earle, J. (2012, Jul 11). Russian monarchy: Romanovs’ fate revealed. Wall Street
The sources were listen on the first post.. However here they are and you can look up each article by searching for title and author on Google. Do you need more help? please let me know
Ferro, M. (1993). Nicholas II: Last of the tsars. New York: Oxford University Press.
Firsov, S. L. (2012). Emperor Nicholas II as an Orthodox Tsar. Russian Studies In History, 50(4), 79-90.
Massie, R. K. (1998, Jul 20). The wrong man for the time. Newsweek, 132, 34.
Shakibi, Z. (2007). Revolutions and the collapse of monarchy: Human agency and the making of revolution in France, Russia, and Iran. London: I.B. Tauris.
Earle, J. (2012, Jul 11). Russian monarchy: Romanovs’ fate revealed. Wall Street
Please make sure to use the sources I provided ONLY. Don’t use any other sources to make citations please.