The six covers of the Unknown Worlds of Science Fiction, a 1975 bi-monthly magazine published by Magazine Management, a parent company of Marvel Comics, and distributed by Curtis Circulation.
It featured stand alone sci-fi strip stories, interviews and articles
A couple of pages showing some of the content.
A page from issue 1, showing Chapter Two of The Day Of The Triffids, by John Wyndham. The Strip is adapted by Gerry Conway, Ross Andru and Ernie Chua.
One of my favourites from issue 4. Enchanted Village by A.E. van Vogt,, and adapted by Don and Maggie Thompson and Dick Giordano.
Finally an ad showing other magazines in the series, including Woodsy's , Deadly Hands of Kung Fu.