In the last century, throughout most Middle Eastern countries, it was common to give the distances between cities in walking distances. For example, Khaybar is ten days' journey by foot to Jeddah. See also. Pacing (surveying) Pace (unit) League (unit) Parasang; Biblical mile; References
A mass-market paperback is a small, usually non-illustrated, inexpensive bookbinding format. This includes the UK A-format books of 110 mm Ã 178 mm (4.3 in Ã 7.0 in) and the US pocketbook format books of a similar size.
Modern paperbacks can be differentiated by size. In the US there are  mass-market paperbacks  and larger  trade paperbacks . In the UK, there are A-format, B-format and the largest C-format sizes.Paperback editions of books are issued when a publisher decides to release a book in a low-cost format. trade paperback, sometimes referred to as a trade paper edition or just trades, is a large-sized paperback book.