Catholic Encyclopedia article on "Ecuмenical Councils:"
https://www.newadvent.org/cathen/04423f.htm This subject will be treated under the following heads:
Definition
Classification
Historical Sketch
The Pope and General Councils
Composition of General Councils
Right of participation
Requisite number of members
Papal headship the formal element of Councils
Factors in the Pope's Co-operation with the Council
Convocation
Direction
Confirmation
Business Methods
The facts
The theory
Infallibility of General Councils;
Correlation of Papal and Conciliary Infallibility
Infallibility Restricted to Unanimous Findings
Promulgation
Is a Council above the Pope?
Has a General Council Power to Depose a Pope?