Since 1948 published by Böhlau in Vienna or Cologne.
Title varies, v. 2, i.e. 4.-8. Lfg., 1892-94: ... hrsg. und erg. von Julius Ficker und Eduard Winkelmann.
Title varies, v. 3, i.e. 9. Lfg., 1901: ... Einleitung und Register bearb. von Franz Wilhelm.
Each v. has also special t.p.
Issued in 9 Lieferungen, 1879-1901.
An expansion of his Regesta Imperii inde ab anno 1198 ...
Paged continuously. Vol. 1, 1.-2. Abth.: [9], viii-liv, [2], 692, [4]; [4], 693-1053, [1] p. Vol. 2: [8], v, [1], 1055-2196 p. Vol. [3]: clx, [2197]-2424 p.