library/library_app/reports/library_book_report.xml

<?xml version="1.0" encoding="UTF-8" ?>
<odoo>
    <record id="paperformat_euro_landscape"
        model="report.paperformat">
        <field name="name">European A4 Landscape</field>
        <field name="default" eval="True" />
        <field name="format">A4</field>
        <field name="page_height">0</field>
        <field name="page_width">0</field>
        <field name="orientation">Landscape</field>
        <field name="margin_top">40</field>
        <field name="margin_bottom">23</field>
        <field name="margin_left">7</field>
        <field name="margin_right">7</field>
        <field name="header_line" eval="False" />
        <field name="header_spacing">35</field>
        <field name="dpi">90</field>
    </record>
    <report id="action_library_book_report"
            string="Library Books"
            model="library.book"
            report_type="qweb-pdf"
            name="library_app.report_library_book_template"
            paperformat="paperformat_euro_landscape"
    />
    <template id="report_library_book_template">
        <t t-call="web.html_container">
            <t t-call="web.external_layout">
                <div class="page">
                    <div class="container">
                        <div class="row bg-primary">
                            <div class="col-3">Title</div>
                            <div class="col-2">Publisher</div>
                            <div class="col-2">Date</div>
                            <div class="col-3">Publisher Address</div>
                            <div class="col-2">Authors</div>
                        </div>
                        <t t-set="author_count" t-value="0"/>
                        <t t-foreach="docs" t-as="o">
                            <div class="row">
                                <div class="col-3">
                                    <h4><span t-field="o.name"/></h4>
                                    <t t-set="author_count" t-value="author_count + len(o.author_ids)" />
                                    (Accum. authors: <t t-esc="author_count" />)
                                </div>
                                <div class="col-2">
                                    <span t-field="o.publisher_id"/>
                                </div>
                                <div class="col-2">
                                    <span t-field="o.date_publisher"
                                          t-options="{'widget':'date'}"/>
                                </div>
                                <div class="col-3">
                                    <span t-field="o.publisher_id"
                                          t-options='{
                                            "widget":"contact",
                                            "fields":["address","email","phone","website"],
                                            "no_marker":true
                                          }'
                                    />
                                </div>
                                <div class="col-2">
                                    <ul class="list-unstyled">
                                        <t t-foreach="o.author_ids" t-as="author">
                                            <li class="media">
                                                <span t-field="author.image_small"
                                                      t-options="{'widget':'image'}"/>
                                                <div class="media-body">
                                                    <p class="mt-0">
                                                        <span t-field="author.name"/>
                                                    </p>
                                                </div>
                                            </li>
                                        </t>
                                    </ul>
                                </div>
                            </div>
                            <div class="row">
                               <div class="col-3">
                                   Count: <t t-esc="len(docs)" />
                               </div>
                               <div class="col-2" />
                               <div class="col-2" />
                               <div class="col-3" />
                               <div class="col-2" />
                            </div>
                        </t>
                    </div>
                </div>
            </t>
        </t>
    </template>
</odoo>