<a href="https://en.wikipedia.org/wiki/Louis_L%C3%A9ger" class="extiw" title="en:Louis Léger">Louis Léger</a>
Unknown author<span style="display: none;">Unknown author</span>
before 1923 <div style="display: none;">date QS:P,+1923-00-00T00:00:00Z/7,P1326,+1923-00-00T00:00:00Z/9</div>
Scanned from the book "History of the Bulgarian Academy of Sciences. Volume 1: 1869-1947"