[osis-core] Questions about osisRefs

[Harry Plantinga]

Let me see if I have osisRefs straight, through some more use cases.
Basically, I'm trying to figure out whether an osisRef refers to 
a particular reference system, or a particular work, or what.

1.  I want to refer to Psalm 20 (KJV reference system) in any version.

	<reference osisRef="Bible.KJV:Psalm.20">

  Do I need to add a <work> element "declaring" Bible.KJV? e.g. 

    <works>
      <work osisWork="Bible.KJV">
	  <title>Holy Bible -- King James Version</title>
	</work>
    </works>

2.  I want to refer to Psalm.20 of the LXX in an English translation

	<works>
	  <work osisWork="lxx_en">
	    <title>Septuagint</title>
	    <language>en</language>
	  </work>
	</works>

	[...]

	<reference osisRef="lxx_en:Psalm.20">

3.  I want to refer to Psalm.20 (KJV reference system) of the English
    LXX.

    [same <work> entry as above]

    <reference osisRef="lxx_en(Bible.KJV):Psalm.20">

Is this right?
DO I also need to declare Bible.KJV in case 3?
If we aren't always "declaring" ref system, how do we tell
a ref system name from a work identifier?

-Harry