{
    "query": {
        "category": "Economics",
        "publication_date": "1971-04",
        "nr_of_items": 2
    },
    "items": [
        {
            "title": "An Econometric Approach to a Marketing Decision Model",
            "subtitle": null,
            "author": "by Ronald E. Frank and William F. Massy",
            "isbn": "9780262561891",
            "publisher": "MIT Press",
            "link_to_publisher": "https:\/\/mitpress.mit.edu\/9780262561891\/an-econometric-approach-to-a-marketing-decision-model"
        },
        {
            "title": "Portfolio Selection",
            "subtitle": "Efficient Diversification of Investments",
            "author": "Harry M. Markowitz",
            "isbn": "9780300013726",
            "publisher": "Yale University Press",
            "link_to_publisher": "https:\/\/yalebooks.yale.edu\/book\/9780300013726\/portfolio-selection"
        }
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}