Diagnosing and Recognizing ODD
ODD should always be formally diagnosed by a doctor, however here are some official sources if you think you have a child with undiagnosed ODD.
Here is the official DSM-5 page on ODD, and what it takes to get a professional diagnosis.
This is a much more in-depth analysis of ODD by The American Academy of Child and Adolescent Psychiatry, also including common secondary diagnosis as well as common treatment methods.
A Guide for Families by the American Academy of Child and Adolescent Psychiatry
Articles about Managing ODD
This Medical Express article is the one I referenced in my site and has other tips and tricks that are very useful.
What to Do if Your Child has Oppositional Defiant Disorder
This PDF is completely dedicated for tips and tricks for managing ODD specifically in a classroom setting, as well as presenting some examples on when to use them.
Oppositional Defiant Disorder: Recommendations for Teachers and for Parents
This article from Attitudemag gives an overview of what ODD is, statistics about the disorder, and goes into detail on the subtypes of ODD.
How to Deal with Oppositional Defiant Disorder(ODD) in the Classroom 