mixing related objects django [duplicate]

I have something like this in my models.py:

class Section(models.Model):
    title = models.CharField(max_length=50)

class Lesson1(models.Model):
    section = models.ForeignKey(Section)
    title = models.CharField(max_length=50)
    ...
    sort_index = models.IntegerField()

class Lesson2(models.Model):
    section = models.ForeignKey(Section)
    title = models.CharField(max_length=50)
    ....
    sort_index = models.IntegerField()

And I need to display them mixed, like this:

section title:
-lesson1 title
-lesson2 title
-lesson1 title

next section title:
-lesson2 title
-lesson2 title
-lesson1 title

Is there a nice way to do this?