Resolution No. 73 of the Council of Ministers of the BSSR «On the Accession of the BSSR to the Protocol on Road Markings of March 1, 1973 to the 1971 European Agreement supplementing the Convention on Road Signs and Signals of 1968»
НАРБ. Ф. 7. Оп. 5. Д. 8857. Л. 89 – 90. The original. Typewriting.