I'm starting with odoo (v10). The following code creates the fields "name" in the model "Category" and "Author" but not in "Book". There is no trace of said field in the views (produces error) nor postgre. Can someone tell me why?
Thank you.

import logging, datetime

from odoo import models, fields, api



class Libro(models.Model):

    _name = 'biblioteca.libro'

    _description = 'Contiene los libros'



    name=fields.Char(string='Titulo')

    tipo=fields.Selection([('a', 'Tipo A'),('b','Tipo B')], string='Tipo de libro')

    prestado=fields.Selection([('s','S'),('n','N')], string='Prestado (s/n)')

    categoria=fields.Many2one(comodel_name='biblioteca.categoria',string='Referencia a categorías')

    autores=fields.Many2many(comodel_name='biblioteca.autor')



class Categoria(models.Model):

    _name='biblioteca.categoria'

    _description='Contiene las categorias'



    name=fields.Char(string='Categoría',size=30)

    libros=fields.One2many(comodel_name='biblioteca.libro',inverse_name='categoria')



class Autor(models.Model):

    _name='biblioteca.autor'

    _description='Contiene los autores'



    name=fields.Char(string='Autor')

    libros=fields.Many2many(comodel_name='biblioteca.libro')