I highly recommend Mary, the Untrodden Portal of God I believe was written by Coniaris.
God bless !
Do you mean the book; The Untrodden Portal of God by George S. Gabriel ?There are many good books about the Theotokos in english:
My favourite is : The Life of the Virgin Mary the Theotokos, by the Holy Apostels Convent-it is great ( within the framework of Holy Scripture, Holy Tradition, Patristics and other ancient writings together with the Liturgical and Iconographic Traditions of the Orthodox Church)
The Most Holy Theotokos , by Archbishop Lazar ( usually I do not like his writings) The Teaching about the Life of the Virgin Mary, and a prayerful contemplation on the Theotokos for each day of the month.
The Repose of our Most Holy and Glorious Lady the Theotokos; by Minos Charitos
The Assumption of our Most Holy Lady the Mother of God, translated from the Menology
Mary and the Fathers of the Church; The blessed Virgin Mary in Patristic Thought
On the Dormition of Mary; Early Patristic Homilies, by Brian E. Daley,
Ancient Traditions of the Virgin Mary's Dormition and Assumption, Stephen Shoemaker, Oxford Studies,
The Image of the Virgin Mary in the Akathistos Hymn, by Leena Mari Peltoma,About the Iconography of the Theotokos:
Icons and Power, the Mother of God in Byzantinum, by Bissera V. Pentcheva,
Images of the Mother of God, Perceptions of the Mother of God in Byzantinum, by Maria Vassilaki
MOTHER OF GOD; Representations of the Virgin in Byzantine Art ( a great book)
Wonderworking Icons of the Theotokos; translated from russian and compiled by Feodor S. Kovalchuk,
Miracle of the Mother of God:
Concealment of sins during Confession is a deadly sin, CTOS
Visions outside the church:http://www.orthodoxinfo.com/ecumenism/visions-outside-the-church.aspx
An Orthodox View of the Virgin Mary:http://www.orthodoxinfo.com/inquirers/theotokos.aspx
Why is Mary considered Ever-Virgin:http://www.orthodoxinfo.com/inquirers/evervirgin.aspx
The Veneration of the Virgin Mary, by Protobresbyter Michael Polsky:http://www.orthodoxinfo.com/general/veneration_mary.aspx
The Council of Ephesus:http://www.piar.hu/councils/ecum03.htmFrom the Spiritual Meadow of John Moschus
......When the old man heard the name of Nestor he was so overcome with fear that this brother would be damned that he fell down and prayed, and begged him to abandon this most evil and pernicious heresy and return to the holy Catholic and Apostolic Church."There is no hope of being saved unless we truly feel and believe that Holy Mary is the Theotokos," he said, "and this is true." Elisabeth is the first to address the Virgin Mary with the sublime salutation of " the Mother of my Lord" ( ee Meeteer tou Kyriou mou). The word Kyrios, Lord that Elisabeth used, was a term wich, among Hellenistic Jews, MEANT ONLY GOD.
from the Life of the Virgin MarySt. Gregor the Theologian:
"If anyone does not accept the Holy Mary as Theotokos, he is without the Godhead."St. Vincent of Lerins:
"Therefore, may God forbid that anyone should attempt to defraud Holy Mary of Her superiority in divine grace and of her special glory. For by unique favor of our Lord and God, She is to be confessed to be the most true and most blessed Mother of God."Everyone, who does not confess the Virgin Mary to be the Theotokos- can not be called Christian !