Unable to find a proper formula to partially match words in one column to another

I need to match words from different columns and give my input regarding the same. For example, if book names given in column A1 matches B1 along with the author names (given on C1 and D1), then it will be called a Safe match. If only the book name matches then Potential match and so on.

The formula I have written is given below:

=IFS(A1=B1,IF(C1=D1,"Safe Match",IFS(A1=B1,IF(C1<>D1,"Potential Match","No Match"))))

There are 2 issues with this. Firstly, I don't need an exact match. I need a partial match which this formula is not giving me. Secondly, I'm getting an error instead of "No Match".