Here is an example on how to parse an xml using lxml and xpaths:

from lxml import etree
namespaces = {'abc': "ABCDEFG.com"}
xmltree = etree.fromstring(xml_string)
items = xmltree.xpath('//abc:Alias/text()', namespaces=namespaces)

print items

As the read_xml()documentation says:

Note: The etree parser supports limited XPath expressions. For more complex XPath, use lxml which requires installation.

Unfortunately, it seems to me this is one of those situations where a "more complex" xpath is needed... So let's use lxml:

from lxml import etree
import pandas as pd

rec = """[your xml response above]"""
doc = etree.XML(rec.encode())

#now to deal with those pesky namespaces
ns = {"x":"http://www.loc.gov/zing/srw/", "y":"http://purl.org/dc/elements/1.1/","z":"http://www.w3.org/2001/XMLSchema-instance"}

#we can now look for the data
rows = []
targets = doc.xpath('//x:record',namespaces=ns)
for target in targets:
    title = target.xpath('//y:title',namespaces=ns)
    date = target.xpath('//y:date',namespaces=ns)
    identifier = target.xpath('//y:identifier[@z:type="tel:ISBN"][1]',namespaces=ns)    
    rows.append([title[0].text.strip(),date[0].text.strip(),identifier[0].text.strip()])

#and, finally, create the dataframe
columns = ['dc:title','dc:date','dc:identifier']
pd.DataFrame(rows,columns=columns)

Output:

     dc:title                       dc:date     dc:identifier
0   [Erg.-H.]. Myst IV Revelation   2004    978-3-8272-9125-7 kart. : EUR 16.95, EUR 17.50...