[Marilize]

The outside barking is a difficult habit to break and unless you can restrict their access, they are going to bark. That said, there are ways that you can entertain them when you need to sleep.

They started barking because they were bored and now they enjoy it. You need to exercise them more, especially before you go to sleep. Try going for a long walk to tire them out. Afterwards, give each of them a kong, chew toy or treat ball, stuffed with treats. After they are finished with the treats, they will be so tired, they will probably sleep until you wake up.

Also, have you considered having them in the house or room with you? They are less likely to bark if they are inside. And you can correct them if they are inside. To correct them, choose a command (e.g. stop it or no bark) and say it when they are barking. After you have said it, jiggle a can of pennies. They hate the sound and won't want to hear it again.

So, to recap: exercise them and give them something to do while you sleep. Correct them when you can, to let them know that it is not alright to bark nonstop.

Good luck! I hope this helps.