C.H. Spurgeon 
Praying in the Holy Spirit [EPUB ebook] 

Praying in the Holy Spirit is one important bible study about the prayer.
A book that will bring growth and knowledge about prayer, and invite him to live with greater intimacy with God.
Written by Charles Spurgeon, important preacher Christian.
Charles Haddon (CH) Spurgeon, 19 June 1834 – 31 January 1892) was a British Particular Baptist preacher. Spurgeon remains highly influential among Christians of various denominations, among whom he is known as the "Prince of Preachers". He was a strong figure in the Reformed Baptist , defending the Church in agreement with the 1689 London Baptist Confession of Faith understanding, and opposing the liberal and pragmatic theological tendencies in the Church of his day.
It is estimated that in his lifetime, Spurgeon preached to around 10, 000, 000 people, Spurgeon was the pastor of the congregation of the New Park Street Chapel (later the Metropolitan Tabernacle) in London for 38 years.
He was part of several controversies with the Baptist Union of Great Britain and later had to leave the denomination.
In 1867, he started a charity organisation which is now called Spurgeon's and works globally. He also founded Spurgeon's College, which was named after him posthumously.