This is a very sticky subject, which normally it wouldn't be. But given the influence and influx of the heresy NPP (New Perspective on Paul), FV (Federal Vision) and its derivatives currently assaulting the Church from without and within, this topic is extremely important but difficult. Why so? Because this is one of the areas which these heresies have attacked, twisted and use as a foundation upon which to build their false teachings. Thus, one must be EXTREMELY CAREFUL to first examine why this subject has become of interest. <img src="/forum/images/graemlins/scratchchin.gif" alt="" />
Genesis 3:1 (ASV) "Now the serpent was more subtle than any beast of the field which Jehovah God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of any tree of the garden?"
The Evil One is very adapt at quoting God's Word but he is even more adapt at twisting God's Word in such a way that it causes one to think in ways which are contrary to that which God intended us to think; questioning God Himself and His perfect will revealed unto us. Such is the way that the Devil works today and has worked from the beginning. He is a mastermind of deceit and confusion, a liar and a murderer of body and soul. Beware of this strong adversary!! (cf. 1Pet 5:8, 9)
Now, to speak to the question directly, i.e., in regard to the "time limit" of Adam's "probation". Of course, just using the term "probation" concedes that there is a set end and disallows the idea of infinite as to time. <img src="/forum/images/graemlins/grin.gif" alt="" /> There is no specific
mention of how long Adam would have had to obey God that I have been able to find in Scripture. But as it is with many other doctrines which Scripture teaches, they are based upon the Analogy of Faith; comparing Scripture with Scripture and as the WCF states it in regard to the knowing of the whole counsel of God it can be known it, "by good and necessary consequence may be deduced from Scripture" (WCF Chapter 1, Section 6). Therefore, I seriously doubt you are going to find anyone whose answer is going to be based upon a specific passage that clearly states that Adam would have merited eternal life if he obeyed for 200 years, or any such thing. <img src="/forum/images/graemlins/wink.gif" alt="" />
Lastly, in answer to your question regarding books or articles on this subject, I think John Murray's article on The Adamic Administration
might be of some help to you.
In His grace,