Universidad de Aconcagua – Sistema de Bibliotecas:
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<br/>Analyzing social settings :  a guide to qualitative observation and analysis / 
John Lofland, Lyn H. Lofland. 
 - 3rd ed. 
 - Belmont, Calif. :  Wadsworth,  1995. 
 - xx, 267 p. :  ill. ;  23 cm.