MacWorld 1991 digital art calendar, featuring winners of the magazine's "Macintosh Masters" graphics contest.
Text states that this is the third year of the calendar, and presumably of the contest, so the first year would have been 1989.
A quick web search did not yield any information about the contest or the calendar. If anyone knows more and wouldn't mind sharing, please reach out! 
True to Apple's aesthetic, the cover is understated and classy, the contents impressive.

Excellent condition, and exceedingly rare.

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If you have any questions please don't hesitate to ask. And while you're here, check out my other listings! I'm always adding more books and other curated vintage goods, and I'm happy to combine shipping.