Logic Problem

• The salesman, who sold 10 vases, isn't Kaufman.
• Ursula went with Usaber to the amusement park one day. The person who was the janitor. All four people are mentioned in this clue.
• Pamela, the person who sold 12 vases, and the salesman go shopping together on Saturdays.
• The person who sold 13 vases lives in the same building as Kaufman and George.
• George, the person who sold 13 vases, and the graphic artist go shopping together on Saturdays.
• Ursula, and Kaufman often watch fights at the salesman's place.
• Pamela went with Maciejewski to the amusement park one day. The person who was the weather-person. All four people are mentioned in this clue.
• The person who sold 10 vases, Ken, and the weather-person went to the movies together.
• Pamela is not the person who sold 13 vases, nor has the last name Maciejewski.
• Usaber sold more vases than the salesman, and more than Ursula.
• The salesman isn't Pamela or the person who sold 12 vases.
• Ken, and Usaber often watch fights at the weather-person's place.
• The weather-person, the person who sold 13 vases, didn't want a copy of Usaber's book.
• The person who sold 20 vases, Kaufman, and the salesman have known each other for years.
• Maciejewski wasn't the person who sold 20 vases. Neither did Ken nor the weather-person.
• The person who sold 20 vases lives in the same building as Quail and Ken.
• The janitor isn't Pamela Usaber.
• The graphic artist, whose first name is Pamela, wasn't the person who sold 12 vases.
• The graphic artist, the person who sold 20 vases, didn't want a copy of Quail's book.