Rujukan:

Design a Cell Phone Stand. (n.d.). Science Buddies. https://www.sciencebuddies.org/stemactivities/build-a-cell-phone-stand

Engineering Design Process. (n.d.). STEM Magnet Academy. http://davis314.weebly.com/engineering-design-process.html

STEM Objectives - NSTA (n.d.). National Science Teaching Association.

https://static.nsta.org/connections/elementaryschool/201312Lott.pdf