C.D. Tica and E.A. Galapon, “Finite-part integration of the generalized Stieltjes transform and its dominant asymptotic behavior for small values of the parameter. II. Non-integer orders”, Journal of Mathematical Physics 60, 013502 (2019).
Get your copy here from the publisher. Compare with the original version of the paper, especially Section 3. Tica-Galapon Journal of Mathematical Physics 60, 013502 (2019) (accepted version)