For more information and to purchase online:

Season 1:
https://www.amazon.com/exec/obidos/ASIN/B0002DB5N6/ref=nosim/happydaysonline3-20

Season 2:
https://www.amazon.com/exec/obidos/ASIN/B0009W5KJU/ref=nosim/happydaysonline3-20

Season 3:
https://www.amazon.com/exec/obidos/ASIN/B000EWBKP8/ref=nosim/happydaysonline3-20

Season 4:
https://www.amazon.com/exec/obidos/ASIN/B000GB5M4M/ref=nosim/happydaysonline3-20

The Complete DVD Collection:
https://www.amazon.com/exec/obidos/ASIN/B06XD15YMF/ref=nosim/happydaysonline3-20

The Complete Series (Germany Version):
https://www.amazon.com/exec/obidos/ASIN/B009P4URJG/ref=nosim/happydaysonline3-20

The Complete Series (Deluxe Edition) (Shout! Factory):
https://www.amazon.com/exec/obidos/ASIN/B0CBS1TTXH/happydaysonline3-20

The Complete Series (Deluxe Editon) (Shout! Factory Special Offers):
https://shoutfactory.com/collections/alf