2
by Gardner, Howard, 1943-
Published 1999
Book
5
9
Book
10
by Piaget, Jean, 1896-1980
Published 1970
Book
11
by Ruisel, Imrich
Published 2004
Book
13
15
by Thagard, Paul, 1950-
Published 2001
Book
17
by Challoner, Jack
Published 2007
Book
20
Published 2000
Book