1054 - Unknown column 'm.manufacturers_name' in 'order clause'

SELECT count(distinct p.products_id) AS total from scot_products p INNER JOIN scot_products_to_categories ptc ON (p.products_id = ptc.products_id AND ptc.categories_id IN ( 6 ) ) INNER JOIN scot_products_description pd ON (p.products_id = pd.products_id AND pd.language_id = '2' ) WHERE p.products_status = '1' ORDER BY m.manufacturers_name ASC

[DB ERROR]