Iran boosts military support in Syria to bolster Assad // Reuters. 21 February 2014.

https://en.wikipedia.org/…/Iranian_involvement_in_the_Syrian_ Civil_War

Iran does not seek indefinite power for Assad, senior diplomat says // The Daily Star (Lebanon). April 4, 2014.

How Iranian general plotted out Syrian assault in Moscow // Reuters. 6 October 2015; Jay Solomon, Sam Dagher. Russia, Iran Seen Coordinating on Defense of Assad Regime in Syria // The Wall Street Journal. 21 September 2015; Israeli official: Iran mastermind went to Russia // Business Insider. 10 September 2015.