1054 - Unknown column 'p.sort_order' in 'order clause'

select distinct p.products_id as id, p.products_image, p.products_price, p.products_quantity, p.products_weight, p.products_model, p.products_tax_class_id, p.products_date_added, p.products_ordered, p.manufacturers_id, m.manufacturers_name, IF(s.status, s.specials_new_products_price, NULL) as special_price, IF(s.status, s.specials_new_products_price, p.products_price) as price, IF(s.status, s.expires_date, NULL) as expires_date, pd.products_name , LEFT(pd.products_description, 180) as description from products p left join manufacturers m on p.manufacturers_id = m.manufacturers_id left join specials s on p.products_id = s.products_id , products_description pd where p.products_status = '1' and p.products_id = pd.products_id and pd.language_id = '1' and s.status = 1 and p.products_quantity > 0 order by p.sort_order, pd.products_name asc limit 0, 3