The Application of Non-orthogonal Laguerre L2 Basis to the Calculation of the Differential and Integrated Cross Sections for the Electron Impact Elastic and Excitation of the 21S, 21P, 23S, 23P States of Helium at Intermediate Energy - Agus Kartono; Theoretical Physics Division, Faculty of Mathematics and Natural Sciences, Institut Pertanian Bogor (Institut Teknologi Bandung, 2009)