This page said that the spelling was incorrect and that it should be Lili & Susie. The fact is that it actually depends on what song you are listening to. In the 80's the duo's name was Lili & Sussie but in 1990 it was changed to Lili & Susie. So if you have any of the older songs:
# Sommar i Natt (1985)
# Stjärnljus (1985)
# Om du kan (1985)
# Stay (1986)
# Candy Love (1986)
# Tokyo (1987)
# Oh Mama (1987)
# Bara du och jag (1987)
# We Were Only Dancing (1988)
# Enkel Resa/Let's Have a Party (1988)
# Jag drömmer om en jul hemma (1988)
# Robert & Marie (1989)
# Okey Okey! (1989)
# Let Us Dance Just a Little Bit More (1989)
the correct artist tag is: Lili & Sussie