Hogan, P. (1974). Playgrounds for free: The utilization of used and surples materials in playground construction. MIT press.
শিকাগো স্টাইলে সাইটেশনHogan, Paul. Playgrounds for Free: The Utilization of Used and Surples Materials in Playground Construction. Cambridge: MIT press, 1974.
এমএলএ সাইটেশনHogan, Paul. Playgrounds for Free: The Utilization of Used and Surples Materials in Playground Construction. MIT press, 1974.
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