Interface Paper

interface Paper {
    authors: string | string[];
    categories?: string[];
    category: null | string;
    comment: null | string;
    doi: null | string;
    has_pdf: boolean;
    journal_ref: null | string;
    pdf_path: null | string;
    published: null | string;
    source: null | string;
    source_fk: number;
    source_id: string;
    summary: null | string;
    tags: string[];
    title: string;
    updated: null | string;
    url: null | string;
    version: number;
}