I emailed the Chess Informant websire and I found the answer to my question. If a game has two stars eg 114** The two stars means that two previously played games were referenced with the current game listed in the Chess Informant. If four stars are listed eg 206**** That means that four previous played games are refrenced.
In the Chess Informant books I noticed that some games have one star next to the game number eg 114* and another game may have four stars 118**** and some games will have no stars listed next to the game number. eg 305
My question is what do the stars next to the game number represent?