APA-viite (7. p.)
ebrary, Inc. (2005). Comfort zones: Planning for a fulfilling retirement, fifth edition (5th ed.). Thomson Course Technology PTR.
Chicago-viite (17. p.)
ebrary, Inc. Comfort Zones: Planning for a Fulfilling Retirement, Fifth Edition. 5th ed. Boston, MA: Thomson Course Technology PTR, 2005.
MLA-viite (9. p.)
ebrary, Inc. Comfort Zones: Planning for a Fulfilling Retirement, Fifth Edition. 5th ed. Thomson Course Technology PTR, 2005.
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