00350nam a2200133 a 450000500170000002000150001708200160003210000150004824500360006326000430009930000200014249000360016270000180019820251203110118.0  a0761951415  a300.72bKRE  aKreft, Ita  aIntroducing multilevel modeling  aLoNew DelhionbSage Publicationsc1998  ax,149p.c23 cm.  aIntroducing Statistical methods  aLeeuw, Jan De