Two or More Works by the Same Author in the Same Year: If you have two sources by the same author in the same year, use lower-case letters (a, b, c) with the year to order the entries in the reference list. Use the lower-case letters with the year in the in-text citation.
The next type of board is the longboard or malibu (mal). The main difference in design is that the nose of the longboard is rounded. Other than that there is no real difference, though shortboards tend to have three fins and longboards tend to have a single fin.
The longboard deck on the other hand, is normally longer, as the name suggests, and instead of curves has two narrow strips at each end, which makes it more stable. Size-wise the longboard vs. skateboard dispute is, to some degree, won by the skateboard, which is smaller and lighter, making it easier to carry around.