DO NOT OPEN THIS LINK!!!!!!
Many years ago when I was a youngster (well younger anyway) there came forth a magazine called "Encycleoedia" which investigated many of the cycling initiatives and developments and it was a "Bible" for alternative cycling
They are now available on line:
Issuu - Encycleopedia
It is interesting to see how various machines developed from early models to the later production models.
However as above - beware as these are addictive, and had a large effect on my wallet as it inspired the piurchase of the Trice, Linear, Birdy, Brompton, Street Machine and others