Possessive Names

Speaking of possessiveness, one of my Turkish/English dictionaries gave the following example of a possessive: Gülru (a woman's name); Gülru'nun (Gülru's).

This switched a light on for me. I had seen this form but didn't understand it. But, following a policy of the Little Prince, once I have a question, I never let it go. I just store it away for future reference.

Now, here's the answer from my textbook: "In written Turkish, proper names are usually separated from the suffix with an apostrophe, in order to avoid confusion."

Examples follow:

• Ali'nin şapkası (Ali's hat)
• Adamın evi (the man's house)
• Adamların evi (the men's house)
• Hanımın kitapları (the lady's books)

But, my textbook says,

If, in a combination of two nouns, the first noun is a modifier rather than a possessor, it does not take a separate suffix.

Then, it cites some examples as follows:

• Ziraat (agriculture); banka (bank); but together Ziraat Bankası (the Agriculture Bank, the largest of the state-owned banks).
• Atatürk Havalimanı (the Atatürk Airport, in Istanbul).
• Üniversite (university); Anakara Üniversitesi (Anakara University)

There may be a connection between these examples and my question regarding arabanın but I don't see it yet.