APA
Willebrands J. S. S. M. P. H. R. A. W. W. G. B. G. L. B. D. A., . (1962). Problems before Unity. Dublin: Helikon LTD.
Chicago
Willebrands J.G.M Sheehan S.G Mailleux P Howda R Abbot W Weigel G Boyer G Leeming B Delahunt A, . 1962. Problems before Unity. Dublin: Helikon LTD.
Harvard
Willebrands J. S. S. M. P. H. R. A. W. W. G. B. G. L. B. D. A., . (1962). Problems before Unity. Dublin: Helikon LTD.
MLA
Willebrands J.G.M Sheehan S.G Mailleux P Howda R Abbot W Weigel G Boyer G Leeming B Delahunt A, . Problems before Unity. Dublin: Helikon LTD. 1962.
