Hogan, P. (1974). Playgrounds for free: The utilization of used and surples materials in playground construction. MIT press.
Dyfyniad Arddull ChicagoHogan, Paul. Playgrounds for Free: The Utilization of Used and Surples Materials in Playground Construction. Cambridge: MIT press, 1974.
Dyfyniad MLAHogan, Paul. Playgrounds for Free: The Utilization of Used and Surples Materials in Playground Construction. MIT press, 1974.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.