Letov Š-218 (1929)
neznámý (unknown)
Letectví, Vol. 9. (1929), No. 6, p. 211-212 - <a rel="nofollow" class="external free" href="https://kramerius.army.cz/search/i.jsp?pid=uuid:6443c4e1-51ee-11e9-b45a-005056b73ae5">https://kramerius.army.cz/search/i.jsp?pid=uuid:6443c4e1-51ee-11e9-b45a-005056b73ae5</a>