300.18 Bla M Black, James A Methods and issues in social research /by/ James A. Black and Dean J. Champion. New York, J. Wiley /c 1976/ ix, 445 p. ilus, 23 cm. Bibliografía al final de los capítulos <a id= "rdfa" about="http://bnjm.sld.cu/cgi-bin/item.py?idficha=bcuhcgrlyfof0220014" property = "oa:link" href="http://www.worldcat.org/oclc/ 503251056 ">WorldCat</a>