To provide different levels of security for the administrator and general
users you'll need to implement user and group security.  You'll find
extensive details of how to do this at:

http://support.microsoft.com/default.aspx?scid=%2Fsupport%2Faccess%2Fcontent%2Fs
ecfaq.asp

If you read the article carefully and take it step by step you shouldn't
find it too difficult to achieve what you want.  Be sure to make a back-up of
the unsecured database first, though, so you have something on which to fall
back if required.

As regards the user interface for querying the database it sounds to me like
you need an unbound form with a combo box from which you can select a
publication and a bound subform within it to return the rows from the sources
table for the selected publication.  If you are using a surrogate key for the
publications table, e.g. a PublicationID autonumber then the combo box would
have this column as its bound column but show the publication name.  For this
you'd set up the combo box along these lines:

RowSource:     SELECT PublicationID, PublicationName FROM Publications ORDER
BY PublicationName;

BoundColum:   1
ColumnCount:  2
ColumnWidths  0cm;8cm

If your units of measurement are imperial rather than metric Access will
automatically convert the last one.  The important thing is that the first
dimension is zero to hide the first column and that the second is at least as
wide as the combo box.

The subform would be based on the Sources table and the LinkMasterFields
property of the subform control would be the name of the unbound combo box in
the parent form, e.g. cboPublication; the LinkChildFields property would be
the name of the foreign key column in the sources table, e.g. PublicationID,
which references the key of the publications table.

Ken Sheridan
Stafford, England