I'd like to recommend 'prison note', but as you know before looking Gramsci book, we must have to see broader history.

I think you can start with Selections From The Prison Notebooks of Antonio Gramsci

Link is as below:

https://abahlali.org/files/gramsci.pdf

I also find it difficult to suggest a reading. Gramsci’s Prison Notebooks are a complex collection, nearly 3000 pages of handwritten notes, often with multiple drafts, and without any clear structure or plan. There are multiple translations, and as I understand still no complete critical edition in English. And even my old selection from the notebooks runs to 450 pages, so simply directing a student directly to them would be overwhelming.

Part of the problem is that Gramsci sometimes employs terms for specific technical purposes and sometimes simply as synonyms for more widely used terms, and sometimes simply in their everyday sense. I have seen it suggested that ‘historical bloc’ is simply a synonym for superstructure.

Depending on the topic I might be more inclined to suggest a reading from someone who has responding to their reading of Gramsci. For example, if I was looking to recommend a reading on the term ‘subaltern’ I would incline to recommend Ranajit Guha’s introduction to the first volume of the Subaltern Studies Group rather than any of the parts of the Prison Notebooks they are responding to.

Looking at my selection of the notebooks (Nowell Smith’s 1973 translation) there is a 9 page section entitled ‘The Formation of the Intellectuals’ which contextualises a definition (on page 12) of the distinction between hegemonic and coercive power (the intellectual, of course, often acting as “the dominant group’s ‘deputies’ exercising the subaltern functions of social hegemony and political government”). That might serve, if you cannot find a better reading, on the concept of hegemony.

However, I am unable to suggest a reading for ‘historical bloc’. In my selections ‘bloc’ seems generally to be used as a synonym for ‘group’ and there appears to be no consistency, certainly no definition, of the term ‘historical bloc’.

I have not worked on Gramsci directly, you can see my thoughts on some elements of the Subaltern studies group work:

Gyatri Spivak https://youtu.be/hMDUOelqkm0

The concept of the 'autonomous domain' https://youtu.be/RO_8GoXAYEs