A photographer has shared his stunning gallery of African sunrises and sunsets. Paul Goldstein says he has spent years trying to photograph the perfect beginning and ending of the Masai Mara day. Thanks to his role as guide for Exodus Travels, there have been countless opportunities to document the beautiful natural spectacle. Photo: “African Fire”: Ostrich at sunset. (Photo by Paul Goldstein/Rex Features)

Every year, in the Rostov region of Russia, a group of 40 young and not so young rural workers compete in the Bison Track Show, or more affectionately known as: Russian Flying Tractor Racing. In front of crowds numbering up to 30,000 people, a series of smoke spilling, monstrous farming machines tear round an 8km mud track, plowing through lakes and dirt mounds, their turbos screaming and tyres scrabbling to find grip.

A retrospective of Garry Winogrand's photography is on display at the Metropolitan Museum of Art in New York. It is the first in 25 years of his work. The show was organized by the San Francisco Museum of Art, and the National Gallery in Washington, DC. Photo: New York, 1965. (Photo by Garry Winogrand/The Estate of Garry Winogrand, courtesy Fraenkel Gallery, San Francisco)

Encyclopedia Britannica editions are seen at the New York Public Library on March 14, 2012 in New York City. Encyclopedia Britannica announced it will be ceasing its print edition of reference books for the first time in its 244-year history to focus solely on digital versions. (Photo by Mario Tama/Getty Images)