When we check the hadith literature we may find out that commentators in first place focussed on the two sahihs and al-Muwatta' which for which one may find much more than ten commentaries, when we move to the so called sunan-books (sunan ibn Majah, abi Dawood, an-Nasa'i) and Jami' at-Tirmdhi we may find less commentaries and often the commentators rely on comments of either the sahihs or al-Muwatta'. However I think that one of both sunan books of an-Nasa'i we find out that the book which was commented is rather his as-Sunan as-Sughra (the small sunnan) than as-Sunnan al-Kubra (the big sunnan). Of course many efforts and books have surely disappeared! So we may miss a lot of the efforts of early scholars. My question is are there any known commentaries on other books (Examples to make a kind of focus) like: - Musnad Ahmad. - Musnad ad-Darimi which would complete the 9 sunnan books and - At-Tabarnis three encyclopaedias (al-Majma' as-Saghir, al-Majma' al-Awsat, al-Majma' al-Kabir) - Musnad al-Bazzar. - al-Mustadrak of al-Hakim - as-Sunan al-Kubra of al-Bayhaqi - Musanaf ibn Abi Shaibah which might also be rather known. There of course much more books which are more or less known like the musnad's of a-Shafi'i and abu Hanifa. If there are not it would be nice if you could provide an explanation why this is the case?