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 deck has a defined nose and tail with a concave in the middle. Skateboard wheels are usually made of polyurethane and range in width from about 1.3-1.5 in (3.3-3.8 cm). While nearly all skateboards have similar shapes and characteristics, their dimensions vary slightly based on use.