Institutes of the Royal Netherlands Academy of Arts and Sciences : progress report (North-Holland Publishing Company, 1968)
1968=58,6; 1969=59,3; 1970=60,2; 1971=61,3; 1972,=61,4; 1973=63; 1974=66; 1975=67; 1976=69; 1977=71; 1978=73; 1979=75; 1980=77; 1981=79; 1982=81; 1983=82 (citonáno z: Staatbibl.zu Berlin)