• https://youtu.be/_p4Hgzm_oNQ
• https://github.com/kpDemos/simpleDatabase/blob/main/simpleDatabase.html

• https://youtu.be/fIs6kK957bY
• https://github.com/kpDemos/imageUpload/blob/main/imageUpload.html

• http://seungangelx.cafe24.com/firebase/simpleDatabase.html
• http://seungangelx.cafe24.com/firebase/imageUpload.html