Reading IS Rocket Science by Louisa Moats
Reading is the fundamental skill upon which all formal education depends. Research now shows that
a child who doesn’t learn the reading basics early is unlikely to learn them at all. Any child who doesn’t learn to read early and well will not easily master other skills and knowledge, and is unlikely to ever flourish in school or in life.
https://www.aft.org/pdfs/teachers/rocketscience0304.pdf
How Words Cast Their Spell by R.M. Joshi, et. al
In 1773, Noah Webster stated that “spelling is the foundation
of reading and the greatest ornament of writing.”1 He was
right. Good spelling is critical for literacy, and it makes writing
much easier—allowing the writer to focus on the ideas
to be conveyed, not the letters needed to put those ideas on paper.
http://www.aft.org/pdfs/americaneducator/winter0809/joshi.pdf
Avoiding the Devastating Downward Spiral
The Evidence That Early Intervention Prevents Reading Failure
By Joseph K. Torgesen
Children who are destined to be poor readers in fourth grade almost invariably have difficulties in kindergarten and first grade with critical phonological skills: their knowledge of letter names, their phonemic awareness (ability to hear, distinguish, and blend individual sounds), their ability to match sound to print, and their other skills in using the alphabetic principle are weak.
https://www.aft.org/newspubs/periodicals/ae/fall2004/torgesen.cfm