GREITHER, Cornelius and Radan KUČERA. Annihilators for the class group of a cyclic field of prime power degree III. Publ. Math. Debrecen. Kossuth Lajos Tudományegyetem, 2015, vol. 86, 3-4, p. 401-421. ISSN 0033-3883.
TRNKOVÁ, Veronika. Enlargement of the group of circular units of a bicyclic field. Journal of Number Theory. 2009, vol. 129, No 1, p. 28-35. ISSN 0022-314X.
POLICKÝ, Zdeněk. On the index of circular units in the full group of units of a compositum of quadratic fields. Journal of Number Theory. 2008, 128/2008, No 4, p. 1074-1090. ISSN 0022-314X.
BULANT, Michal. On Washington group of circular units of some composita of quadratic fields. Math. Slovaca. Bratislava, 2005, vol. 55, No 1, p. 39-46. ISSN 0139-9918.
KUČERA, Radan. A note on circular units in Zp-extensions. Journal de Théorie des Nombres de Bordeaux. Bordeaux, Francie: Institut de Mathématiques de Bordeaux, 2003, vol. 15, No 1, p. 223-229. ISSN 1246-7405.