dˈʊɹɹɪŋ ðɪs pˈiəɹɪəd hiː pˈʌblɪʃt ðə hˈændboʊk dˈɛɹ wˈeɪpəŋkˌʌnd mˈænjuːəl ʌv hˈɛɹəldɹi wˌɪtʃ wʌz ɐn ɪmpˈoːɹtənt ɐdˈɪʃən tə ðə bˈɑːdi ʌv wˈɜːk ˌɔn dˈʌtʃ hˈɛɹəldɹi.
During this period he published the Handboek der Wapenkunde (Manual of Heraldry) which was an important addition to the body of work on Dutch heraldry.