00370pab a2200133 454500008004000000100002200040245008200062260000900144300001400153362000800167650001600175650001400191773003100205180718b1996   xxu||||| |||| 00| 0 eng d  aLeydesdorff, Loet  aLuhmann's sociological theory: its operationalization and future perspectives  c1996  ap.283-306  aJun  aBiographies  aSociology  aSocial Science Information