00295nam a2200109 a 450000500170000008200160001710000180003324500550005126000440010630000120015050000230016220251203112126.0  a519.52bAVA  aAvadhani, M S  aTheory of sample surveys and fields of application  aHyderabadbPatanjali Publicationsc1998  ap.IX-20  aincludes reference