Supermind by Henry Evans
The magician deals groups of cards to 7 spectators and asks each one to think of a card. The cards are put together and the magician not only guesses all of them, but who each one belonged to. A remake of Paul Fox's game
Specific References
The magician deals a group of cards to each of seven spectators and ask them to shuffle the cards and think of any of them. Then all cards are put together reassembling the deck. The deck is shuffled and the magician takes it for the first time and starts spreading the cards for himself. After some concentration he names some cards at random and guess the chosen cards, also saying who chose which card.
The magician deals groups of cards to 7 spectators and asks each one to think of a card. The cards are put together and the magician not only guesses all of them, but who each one belonged to. A remake of Paul Fox's game