Here's the official link.

The answer is yes, as long as they don't violate copyright, trademark, or a few other rules:

3.3 Authorized Cards Players may use any cards from special sets, supplements, and promotional printings that, unaltered, meet the following conditions:

• The card is published by Wizards of the Coast

• The card has a standard Magic back

• The card does not have squared corners

• The card has black or white borders

• The card is not damaged or modified in a way that might make it marked

• The card is otherwise legal for the tournament as defined by the format

Unglued and Unhinged basic land cards are allowed in sanctioned Magic tournaments. Players may use cards from the Alpha printing only if the deck is in opaque sleeves. Players may use otherwise-legal non-English and/or misprinted cards provided they are not using them to create an advantage by using misleading text or pictures. Official promotional textless spells are allowed in DCI-sanctioned Magic tournaments in which they would otherwise be legal. Artistic modifications are acceptable, provided that the modifications do not make the card unrecognizable or contain substantial strategic advice. The Head Judge is the final authority on acceptable cards for a tournament.