Dreyfuss, Henry, Symbol Sourcebook, published 1984, © 1972 by Henry Dreyfuss. p. 191, Graphic Form Symbols, see “Hydraulic Reservoir, 158” on p. 3 of attached PDF. |
Vector—Illustration of a long shadow document icon with a blood drop, posted at 123RF, posting date not given, © Jan. 5, 2016 123RF Limited 2005-2016. [online], [site visited Jan. 5, 2016]. Available from Internet, <URL: http://www.123rf.com/photo—42315716—stockvectorillustrationofalongshadowdocumenticonwithablooddrop.html>. |
Rain Drop on Paper Set Original Vector Illustration, posted at 365PSD, posting date not given, © 2010-2016 365PSD.com. [online], [site visited Jan. 5, 2016]. Available from Internet, <URL: http://365psd.com/premium/raindroponpapersetoriginalvectorillustrationai8compatiblefile11091>. |
Oil drop icon with a document, posted at Depositphotos, posting date not given, © 2009-2016. Depositphotos, Inc. [online], [site visited Jan. 6, 2016]. Available from Internet, <URL: http://depositphotos.com/60613311/stockillustrationoildropiconwitha.html>. |