Page 116 - Building Digital Libraries

General-Purpose Technologies Useful for Digital Repositories

<marc:subfield code=“a”>LC also has 1879 edition measuring 92 x 84 cm., which includes a list of
railroad stations and distances.</marc:subfield>
</marc:datafield>
<marc:datafield tag=“510” ind1=“4” ind2=“ “>
<marc:subfield code=“a”>LC Railroad maps,</marc:subfield>
<marc:subfield code=“c”>280</marc:subfield>
</marc:datafield>
<marc:datafield tag=“500” ind1=“ “ ind2=“ “>
<marc:subfield code=“a”>Description derived from published bibliography.</marc:subfield>
</marc:datafield>
<marc:datafield tag=“520” ind1=“ “ ind2=“ “>
<marc:subfield code=“a”>Detailed township map showing drainage, cities and towns, county and town-
ship boundaries, roads, and railroads.</marc:subfield>
</marc:datafield>
<marc:datafield tag=“500” ind1=“ “ ind2=“ “>
<marc:subfield code=“a”>County population in upper left.</marc:subfield>
</marc:datafield>
<marc:datafield tag=“530” ind1=“ “ ind2=“ “>
<marc:subfield code=“a”>Available also through the Library of Congress Web site as a raster image.</
marc:subfield>
</marc:datafield>
<marc:datafield tag=“650” ind1=“ “ ind2=“0”>
<marc:subfield code=“a”>Railroads</marc:subfield>
<marc:subfield code=“z”>Ohio</marc:subfield>
<marc:subfield code=“v”>Maps.</marc:subfield>
</marc:datafield>
<marc:datafield tag=“752” ind1=“ “ ind2=“ “>
<marc:subfield code=“a”>United States</marc:subfield>
<marc:subfield code=“b”>Ohio.</marc:subfield>
</marc:datafield>
<marc:datafield tag=“852” ind1=“0” ind2=“ “>
<marc:subfield code=“a”>Library of Congress</marc:subfield>
<marc:subfield code=“b”>Geography and Map Division</marc:subfield>
<marc:subfield code=“e”>Washington, D.C. 20540–4650 USA</marc:subfield>
<marc:subfield code=“n”>dcu</marc:subfield>
</marc:datafield>
<marc:datafield tag=“856” ind1=“4” ind2=“1”>
<marc:subfield code=“d”>g4081p</marc:subfield>
<marc:subfield code=“f”>rr002800</marc:subfield>
<marc:subfield code=“u”>http://hdl.loc.gov/loc.gmd/g4081p.rr002800</marc:subfield>
<marc:subfield code=“q”>c</marc:subfield>
</marc:datafield>
</marc:record>
</marc:collection>

While the above record is well structured, and would be easy to process,
the ability to process this document efficiently and quickly generally isn’t
directly supported within most web-based programming languages. For this
reason, communication of this data between most applications would occur
in JSON. We can re-serialize the above record into JSON:

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