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.
Most boards measure 84 to 150 centimetres (33 to 59 in) in length while widths vary from 22.8 to 25.4 centimetres (9.0 to 10.0 in). There are several longboard shapes, such as pintails, swallowtails, flat-nose riders, drop-through decks, drop decks and boards with the same shape as a standard skateboard.
A surfboard, invented in ancient Hawaii, is an elongated platform used to support an individual standing on them while breaking a wave. They are made of polyurethane or polystyrene foam covered with layers of fiberglass cloth, and polyester or epoxy resin, making them light, strong, buoyant and maneuverable.