Welcome to the United Nations 
OHCHR 
International standards
Special Rapporteur on the right to education
Universal Declaration of Human Rights:
"Education shall be free, at least in the elementary and fundamental stages. Elementary education shall be compulsory."
"Parents have a prior right to choose the kind of education that shall be given to their children"
Article 13 International Covenant on Economic, Social and Cultural Rights:
"Primary education shall be compulsory and available free for all."
"The States parties to the present Covenant undertake to have respect for the liberty of parents ... to choose for their children schools, other than those established by the public authorities, which conform to such minimum educational standards as may be laid down or approved by the State and to ensure the religious and moral education of their children in conformity with their own convictions.
No part of this article shall be construed so as to interfere with the liberty of individuals and bodies to establish and direct educational institutions, ..."
Article 18 International Covenant on Civil and Political Rights:
"The States Parties to the present Covenant undertake to have respect for the liberty of parents ... to ensure the religious and moral education of their children in conformity with their own convictions.”
"States Parties recognize the of the child to education, and with a view to achieving this right progressively and on the basis of equal opportunity, they shall, in particular:
(a) Make primary education compulsory and available free for all"…
"No part of [articles 28 and 29] shall be construed so as to interfere with the liberty of individuals and bodies to establish and direct educational institutions…";
Article 10 Convention on the Elimination of all forms of Discrimination against women
UNESCO Convention against Discrimination in Education
European Convention on Human Rights and Fundamental Freedoms, Protocol 1, Article 2:
"No person shall be denied the right to education. In the exercise of any functions which it assumes in relation to education and to teaching, the State shall respect the right of parents to ensure such education and teaching in conformity with their own religious and philosophical convictions.";