Ha. Mavromatis, NEW SUMMATION EXPRESSIONS OBTAINED BY COMBINING PERTURBATION-THEORY FORMALISMS, International journal of computer mathematics, 50(1-2), 1994, pp. 119-123
New perturbation theory expressions obtained by Kim and Sukhatme [''Al
ternative approach to nonrelativistic perturbation theory'', J. Phys.
A 25 (1992) L647-L650] are equated to standard perturbation theory exp
ressions in order to obtain new mathematical series results. Several s
uch new results are derived and discussed.