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See also my list of links to my other RG documents:
https://www.researchgate.net/publication/325464379_Links_to_my_RG_pages
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Original question posted on May 16, 2018: Are there extensions of the concept of angles between two planes? The concept of angle between two planes in the ordinary 3-dimensional space is well-known. Are there extensions of this concept to angles between two vector subspaces of a vector space?
Improved question posted on May 17, 2018.
I have posted a list of references about angles between two vector subspaces on the following Web page:
https://www.researchgate.net/project/Study-of-angles-between-vector-subspaces
My improved question is in the following two parts:
Part 1: Are there references that are not on this list?
Part 2: Which of these references is the best?
I will add to my list any new references and any good comment about these references, with full credit to the first who finds it.