Text ( visual ) : unmediated Towards an improved international reference ionosphere : proceedings of the URSI/COSPAR Workshop held in Stare Zagora, Bulgaria, 30th August-3rd September 1983 / edited by K. Rawer, C.M. Minnis, and K.B. Serafimov. -- 1st ed. -- Oxford : Published for the Committee on Space Research by Pergamon Press , 1984. -- vi, 171 p. : ill. ; 28 cm. -- (Advances in space research ; v. 4, no. 1). -- Includes index. -- ISBN 0080315119 ; (BA35286832) ; https://ci.nii.ac.jp/ncid/BA35286832 Author Heading(s): Rawer, K. (Karl) ; Minnis, C. M. ; Serafimov, Kiril. -- Classification(s): LCC : QC881.2.I6 ; DC19 : 538/.767. -- Subject Heading(s): LCSH : Ionosphere -- Mathematical models -- Congresses