There is a good resource that discusses many aspects of armored warfare from the first days to present times, that is Youtube. Fate would have it that I just watched a video between two of my favorite Youtubers Ian from Forgotten Weapons and "the Chieftain" where they discussed your last question specifically: https://www.youtube.com/watch?v=yF4xxYXwLok @ 45:08.
According to the online Tank Museum "HE was available to the 2-Pounder gun, but British military thinking was that firing Explosive Shells was the job of the Artillery. As such, towed 2-Pounder crews deployed by the Royal Artillery were equipped with HE ammunition, but Tanks, designed for infantry support such as the Matilda II, were not equipped with them."
For more detailed information the 2-pdr HE controversy see https://tanks-encyclopedia.com/ww2/gb/AT-guns/2-pounder.php
Regarding the 2-pdr not firing an HE shell, I'm not sure on the technical specifics, but I know that from the doctrinal standpoint British command did not want/think anti-tank units should be wasted on engaging soft targets (at least before 3rd Alamein). They thought that commanders, lower infantry commanders in particular, would be apt to waste them as close-support weapons thereby stripping them of their real purpose. True their Bofors could have offset this somewhat but their conceptual approach to combined-arms normally precluded it from happening effectively.
There is a workable 2009 article on the 2 Pounder Anti-Tank Gun at the following link:
...that has a table of what ammunition was produced for the "Ordnance QF 2-pounder" and when.
There is a vast literature on the tanks of World War II and their armament. Two things mystify me. For the first half of the war, most British tanks were armed with two-pounder guns. These were 40 mm cannon that fired an armor-piercing shell that was effective against all German tanks at the beginning of the war, and pretty effective even after the Germans improved their tanks and armor in 1942.
Dear Arthur and Robin,
Thank you so much for your very interesting replies.
I will certainly look for material related to your suggestions.
I'm not sure if this is what you're looking for, but in the US (and other countries) clinicians practicing in community settings have established practice-based research networks to collect data relevant to their practices. If you search on *practice-based research network* in www.pubmed.gov you will find a number of explanatory articles from the past 30-40 years.
I do not know whether this qualifies, but any time that there has been in any science, a sharp division in the interpretation of a phenomenon, two sides will generally appear. If the differences persist for any period, they will tend to form at least informal groups, combating one-another in the literature.
I am looking for historical case studies of collectives of scientists, who collaborated with a common agenda, in the twentieth century. There are several studies of naturalist societies and associations of scientists in "Enlightenment" era Europe. But I think there are fewer studies of collectives and organizations founded in the twentieth century, especially those founded outside Europe. Some twentieth century studies I have come across include:
If I may make a suggestion (and forgive me if someone has already made you aware of this), but there are two moderated Facebook groups, both named World History Teachers, and a third, World History Association Teachers, where those "in the trenches" of teaching World History currently communicate ideas and requests. As I am not sure how many of them are also members of H-World, might I suggest posting an inquiry to both of those lists as well as to the AP World History Teachers FB group (I am not a member of that group, but others here may be and can help with that request).