Comments and reply regarding Heck (2003) “On Helmert’s methods of condensation”

Tscherning, C.C. | Online Contents | 2005

Gravity reduction using a general method of Helmert’S condensation

Novák, P. | Online Contents | 2007

Downward continuation of Helmert's gravity

Vaníček, P. / Sun, W. / Ong, P. et al. | Online Contents | 1996

A Revision of Helmert's Second Method of Condensation in Geoid and Quasigeoid Determination

Heck, B. / International Association of Geodesy | British Library Conference Proceedings | 1993

Die wissenschaftliche Ausstrahlung Helmert's in die Gegenwart

Wolf, H. | UB Braunschweig | 1970