text Amsterdam Mathematisch Centrum 1969 Ind 118 p. : ill. ; 25 cm. 118 p. : ill. ; 25 cm. Bibl.: p. 112-118 VERHOEFF, J. MATHEMATICS 511.135 511.135VERe INLIS000000000008787 Converted from MARCXML to MODS version 3.5 using MARC21slim2MODS3-5.xsl (Revision 1.106 2014/12/19)