This image is a derivative work of the following images: File:Pulley_composite_1-12.svg licensed with Cc-by-2.5, Cc-by-sa-3.0-migrated, GFDL 2013-01-26T13:29:44Z...
This image is a derivative work of the following images: File:Four_pulleys_FH.svg licensed with Cc-by-2.5, Cc-by-sa-3.0-migrated, GFDL 2013-01-20T23:31:21Z...
