The 'subjects' collection provides information about book subjects. To retrieve corresponding books you can use 'subject_id' to search in the books collection.

The base URL for the subjects collection access is:

Arguments

name

Performs a search on the subject name. For example:

/api/subjects.xml?access_key=Z&index1=name&value1=astronomy+teaching

The search follows the same rules and syntax as the search on the website itself -- you can group words together using double quotes, all non-ignored words must be present in the results.

category_id

Retrieving subjects listed in the given category by that category ID. Example:

/api/subjects.xml?access_key=Z&index1=category_id&value1=science.biology.history

subject_id

Retrieving subject data by ISBNdb.com's subject ID. Returns at most one match. Example:

/api/subjects.xml?access_key=Z&index1=subject_id&value1=molecular_biology

Results

<?xml version="1.0" encoding="UTF-8"?>
<ISBNdb server_time="2006-01-13T12:13:14">
 <SubjectList total_results="2" page_size="10" page_number="1" shown_results="2">
  <SubjectData subject_id="orthodontics_examinations_questions_etc" book_count="2"
               marc_field="652" marc_indicator_1="" marc_indicator_2="">
   <Name>Orthodontics -- Examinations, questions, etc</Name>
  </SubjectData>
  <SubjectData subject_id="orthodontics_diagnosis_examinations_questions_etc" book_count="3"
               marc_field="650" marc_indicator_1="" marc_indicator_2="0">
   <Name>Orthodontics -- Diagnosis -- Examinations, questions, etc</Name>
  </SubjectData>
 </SubjectList>
</ISBNdb>

In addition to common 'results' blocks the book subjects collection adds some that are subjects specific. The syntax remains the same -- comma separated values in the 'results' argument.

categories

Shows a list of categories this subject is listed in. For example:

/api/subjects.xml?access_key=Z&results=categories&index1=subject_id&value1=love_poetry_english

<?xml version="1.0" encoding="UTF-8"?>
<ISBNdb server_time="2006-01-19T16:14:16">
 <SubjectList total_results="1" page_size="10" page_number="1" shown_results="1">
  <SubjectData subject_id="love_poetry_english" book_count="36" marc_field="650" marc_indicator_1="0" marc_indicator_2="">
   <Name>Love poetry, English</Name>
   <Categories>
    <Category category_id="genres.poetry.love">Love</Category>
    <Category category_id="society.interpersonal_relations.love.poetry">Poetry</Category>
   </Categories>
  </SubjectData>
 </SubjectList>
</ISBNdb>

structure

Shows what the subject consists of. For example:

/api/subjects.xml?access_key=Z&results=structure&index1=subject_id&value1=artificial_intelligence_data_processing

<?xml version="1.0" encoding="UTF-8"?>
<ISBNdb server_time="2006-01-13T12:13:14">
 <SubjectList total_results="1" page_size="10" page_number="1" shown_results="1">
  <SubjectData subject_id="artificial_intelligence_data_processing" book_count="95"
               marc_field="650" marc_indicator_1="0" marc_indicator_2="">
   <Name>Artificial intelligence -- Data processing</Title>
   <SubjectStructure>
    <SubjectElement text="Artificial intelligence" type="Topical Term" marc_subfield="a"/>
    <SubjectElement text="Data Processing" type="General" marc_subfield="x"/>
   </SubjectStructure>
  </SubjectData>
 </SubjectList>
</ISBNdb>

Attributes in the SubjectData tag have the following meaning:

• marc_field - where available this represents the value corresponding to MARC standard. See http://www.loc.gov/marc/bibliographic/ecbdhome.html for details.
• marc_indicator_1 and marc_indicator_2 - two characters from this MARC record's indicator columns, where available.

Attributes in the SubjectElement tag have the following meaning:

• text - literal text of the subject element. Typically, but not in all cases, subject name is formed by combining texts of its elements separated by double-dash.
• type - an ISBNdb.com specific type loosely based on the MARC field and subfield information.
• marc_subfield - MARC subfield symbol, where available.