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.
I get asked that a lot. There are many differences as well as similarities between the two. Often looking very similar, both folding cartons and rigid boxes are indeed boxes used for packaging and both are made of paperboard. Paperboard is basically thick paper that is sturdy enough to be used for packaging.