Many of Fr Daniel Sysoev's writings are now available to order in physical book form in English and Russian (with more English editions to follow, I am informed) from the Orthodox Internet Store of Rev. Daniel Sysoev.
One of if not THE most significant of the New Martyrs of the 21st Century under the Sword of Islam, the righteous Fr. Daniel Sysoev of Moscow was shot and killed by a Muslim in front of the altar at the church he founded.
Fr Daniel was not any ordinary casualty of Islam's renewed war on Christians. He was a towering figure in the Russian Orthodox Church, a theologian, writer, evangelist and missionary, who engaged in open debate with Muslims, and converted some eighty or more of them from Islam to the Orthodox Faith, including a number of Wahhabi extremists.
Fr. Daniel also felt a special burden to properly catechize the Russian faithful in the Orthodox Way. The Russian Orthodox Church only recently emerged from seventy years of brutal repression and persecution under the Soviet communist tyranny, and as a result, the level of understanding of the average Christian in Russia since the early 1990s was at a very modest level. Many of Fr. Daniel's books therefore address such "basic" topics as church attendance, frequent communion, marrying non-Orthodox, etc.
Special thanks to Anthony for informing me of this important development! I hope to purchase many of these titles and encourage you to do the same to help support this good work. I will post updates as specific titles by Fr. Daniel related to Orthodoxy and Islam become available in English.
For more on New Martyr Priest Daniel Sysoev, see my special resource page.