What does it mean? "To the best of [their] knowledge” or mine"

Question

Whatever the true significance of their results may be, Chen and Petkova’s effort to “disentangle[]” the heretofore combined “effects of average variance and average correlation on stock returns” much more “clearly” highlights “the role of average variance” and correlation in explaining the low-volatility anomaly.120 “To the best of [their] knowledge” or mine, these effects have “not been documented before.”

Answer 1

تا جایی که اونا میدونند یا من میدونم...

Answer 2

در حدود دانش آنها یا دانش من