00382nam a22001337a 450000500170000000800410001702000140005804100080007208200180008010000200009824500660011826000480018430000160023220260424105639.0260424b        |||||||| |||| 00| 0 eng d  a070574715  aeng  a301.32bSIN/I  aSinger, S. Fred  aIs Ther an Optimum Level of Population ?c/ by S. Fred Singer  aNew York:bMcgraw- Hill Book Company,c1971  axiv, 426p.;