Pen and Ink TURKISH WHIRLING DERVISHES Artist???

Bought these two original pen and ink drawings (beautiful fluidity in the lines) today. Five figures depicted in one, three in the other. Figured out that the drawings subject matter are Turkish "whirling dervishes" who dance in a state of meditation. Does anyone recognize the signature? Looks like the name begins with R or P ... my searches so far haven't produced a match although there are some similar drawings out there. Let me know if you can discover who the artist is! I'll post here if I figure it out myself. Thanks!