In academia, we call those parts "footnotes". There are 38 provided in the article. The uniqueness of a zygote is not news in the field of molecular biology as the textbooks cited confirm. If the biology books cited in the article are not at your local library, you may use these online sources:
When Human Life Begins | American College of Pediatricians
https://acpeds.org › position-statements › when-human-...
The American College of Pediatricians concurs with the
body of
scientific evidence that corroborates that a
unique human life starts when the
sperm and egg ...
A Distinct Human Organism - NPR
https://www.npr.org › templates › story › story
Nov 22, 2005 — The embryonic, fetal, infant, child and adolescent stages are stages of development of a determinate and enduring entity -- a
human being -- who ...
Defining the Biological Identity of the Unborn: A Scientific ...
https://scholarspace.jccc.edu › cgi › viewcontent
PDF
by P Slon · 2019 — each other in order to complete the full
human genome of a
human being after fertilization. The resulting
zygote has a
unique genetic composition that is ...