My advise is to start by designing the database properly, that is using normalisation to ensure tables only contain data about one thing (book, journal, etc.) and that attributes are stored in the right table.
If in the future it creates performance problems you can de-normalise it into less tables, but this is unlikely to be a problem unless you have a huge database.
Create one table that will hold the common attributes for all references.
Create separate tables to hold the attributes that are specific to each type of reference.
The other issue is whether you will have many references to a single work,e.g. hundreds of references to a particular journal. Normalisation would then suggest you have a table that holds the journals (title, author,journal), a table that holds the reference information that is specific to journals (article, page), and another table that holds data that is common to all references (date of reference, type of reference).
