Encyclopædia Britannica "Quinisext Council". Encyclopædia Britannica. Retrieved February 14, 2010. "The Western Church and the Pope were not represented at the council. Justinian, however, wanted the Pope as well as the Eastern bishops to sign the canons. Pope Sergius I (687–701) refused to sign, and the canons were never fully accepted by the Western Church".
"Pentarchy". Encyclopædia Britannica. Retrieved February 14, 2010. "Pentarchy. The proposed government of universal Christendom by five patriarchal sees under the auspices of a single universal empire. Formulated in the legislation of the emperor Justinian I (527–65), especially in his Novella 131, the theory received formal ecclesiastical sanction at the Council in Trullo (692), which ranked the five sees as Rome, Constantinople, Alexandria, Antioch, and Jerusalem".
ccel.org
Schaff's Seven Ecumenical Councils: Introductory Note to Council of Trullo: "From the fact that the canons of the Council in Trullo are included in this volume of the Decrees and Canons of the Seven Ecumenical Councils it must not for an instant be supposed that it is intended thereby to affirm that these canons have any ecumenical authority, or that the council by which they were adopted can lay any claim to being ecumenical either in view of its constitution or of the subsequent treatment by the Church of its enactments."
ewtn.com
See official Greek translation of the Roman Missal and the documentThe Greek and Latin Traditions about the Procession of the Holy Spirit by the Pontifical Council for Promoting Christian Unity, which states: "The Catholic Church has refused the addition καὶ τοῦ Υἱοῦ to the formula τὸ ἐκ τοῦ Πατρὸς ἐκπορευόμενον in the Greek text of the Nicene-Constantinopolitan Symbol, even in its liturgical use by Latins"
google.cat
books.google.cat
Diehl, Charles. «1: Leo III and the Isaurian Dynasty (717-802)». A: The Cambridge Medieval History. IV: The Eastern Roman Empire (717-1453). Cambridge: Cambridge University Press, p. 21. ISBN 9785872870395 [Consulta: 1r febrer 2016]. «... Tarasius... skilfully put forward the project of an Ecumenical Council which should restore peace and unity to the Christian world. The Empress [...] summoned the prelates of Christendom to Constantinople for the spring of 786. ... Finally the Council was convoked at Nicaea in Bithynia; it was opened in the presence of the papal legates on 24 September 787. This was the seventh Ecumenical Council.»