Doctoral dissertation or master's thesis APA formet

For a doctoral dissertation or master's thesis available from a database service, use the following reference template (APAv6 p. 207):
Author, A. A. (2003). Title of doctoral dissertation or master's thesis (Doctoral dissertation or master's thesis). Retrieved from Name of database. (Accession or Order No.)
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Yet the very first example following this template:
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Example 40. Master's thesis, from a commercial database (p. 208):
McNeil, D. S. (2006). Meaning through narrative: A personal narrative discussing growing up with an alcoholic mother (Master's thesis). Available from ProQuest dissertations and Theses database. (UMI No. 1434728)
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offers 'alternate' descriptive text, the phrase "Available from..." rather than the template's "Retrieved from...". Are these two phrases equally valid? Had I used my own phrase, e.g., "Located in...", would this be equally valid?
Also, when it comes to what the 'reference template' calls the 'Accession or Order No.' is there flexibility in how that number is introduced? Example 40 above uses the text prefix 'UMI No.' The ProQuest Dissertations and Theses database uses the prefix 'Publication No.'. Are both prefixes equally valid when composing citations compliant with APA 6th style guidelines?

Panasuk, N. (2008). What variables appear to work in stress management programs in the workplace and how effective are these programs? Unpublished master’s thesis, The College of St. Scholastica, Duluth, Minnesota.