Parents. https://www.parents.com/baby/development/behavioral/8-weird-stages-of-babys-development/
Diakses pada 31 Maret 2020Simply Psychology. https://www.simplypsychology.org/psychosexual.html
Diakses pada 31 Maret 2020AAP. https://www.aap.org/en-us/about-the-aap/aap-press-room/aap-press-room-media-center/Pages/Thumbsucking.aspx
Diakses pada 31 Maret 2020Very Well Mind. https://www.verywellmind.com/freuds-stages-of-psychosexual-development-2795962
Diakses pada 31 Maret 2020Very Well Mind. https://www.verywellmind.com/what-is-a-fixation-2795188
Diakses pada 31 Maret 2020Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/expert-answers/starting-solids/faq-20057889
Diakses pada 31 Maret 2020BMC Chemistry. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6661842/
Diakses pada 18 November 2020