Published 1994

Published in Fulfillment in the Philippines (VII). (1992)

Published 1991

Published 1991

Published in E.J. Halsema--colonial engineer (XV). (1988)

Published in E.J. Halsema--colonial engineer (XIV). (1988)

Published in E.J. Halsema--colonial engineer (XIII). (1988)

Published in E.J. Halsema-colonial engineer (X). (1987)

Published in E.J. Halsema--colonial engineer (X). (1987)

Published in E.J. Halsema--colonial engineer (XI). (1987)