@book{Ropp, author = {Ropp, R. S. de}, title = {Man against aging, New York (Grove Press) 1962.}, language = {en} } @article{Ropp, author = {Ropp, R. S. de}, title = {Drugs, Yoga, and Psychotransformism}, series = {J. Needleman and D. Lewis (Eds.), On the Way to Self Knowledge, New York (Alfred A. Knopf) 1976, pp. 148-181.}, journal = {J. Needleman and D. Lewis (Eds.), On the Way to Self Knowledge, New York (Alfred A. Knopf) 1976, pp. 148-181.}, language = {en} }