Sri Ramnujaye Namha

Velukkudi Swamigalkku Namaskaaram

I have certain questions and clarifications regarding Govinda Naamavali ..

When was it composed and by whom? Is there a standard version, because i find few different versions at different places, 90% of naamams are same but there are minor variations.

Where can i find the meaning of these naamams? are they any past upanyaasams by devareer?

I have few clarifications or confirmations to know which is the right nammam:

1. Abhayahastha Pradarshana Govinda or Abhayahasta Govinda
2. The name after above is Matsyavatara Govinda or Aksaya Varada Govinda 
3.  Salagramadhara Govinda or Salagrama hara  Govinda
4. Ekaswaroopa Govinda or Ekatva roopa Govinda
5. towards the last few paras is Vajramakutadara Govinda repeated as in early para or is it Vajrakavachadhara Govinda?
6. Bhakta Rakshaka Govinda or Bhakta Taraka Govinda
7. Apanivarana Govinda or Abhannirasada Govinda
8. Rathnakireeta Govinda and Raamnujanutha Govinda..these are included in the last paragraph?
9. In the last paragraph  is it Paramadayaloo Govinda or PAdma dalaksha Govinda?
10. Tirumalavasaa Govinda or Tirumalanivasaa Govinda

Adiyen