found: Work cat.: Eliason, R.E. Keyed bugles of the United States, 1972: p. 5 (keyed bugles are soprano brass instruments with side holes and keys like a clarinet or saxophone; variously called the Royal Kent Bugle, patent Kent Bugle, or keyed bugle)
found: Dudgeon, R.T. The keyed bugle, 1993.
found: Dudgeon, R.T. The keyed bugler's companion ... keyed bugle, 1987.
found: New Grove, 2nd ed., WWW site, May 31, 2001(keyed bugle, key bugle, Kent bugle, Royal kent bugle, Kent horn; a conical, wide-bore soprano brass instrument with sideholes controlled by keys similar to those found on woodwind instruments. It is the precursor of the modern flugelhorn. In the Hornbostel-Sachs system it is classified as a trumpet)