SELECT
c.country_code, c.country_name,
m.mountain_range
FROM
mountains_countries AS mc
INNER JOIN mountains AS m
ON mc.mountain_id = m.id
INNER JOIN countries AS c
ON c.country_code = mc.country_code
WHERE c.country_name IN ('Bulgaria', 'Russia',
'United States')
ORDER BY c.country_code ASC, m.mountain_range ASC