Heuvelmans wrote many other books and articles, only a few of which have been translated into English. His works sold well among general audiences but saw little attention from mainstream scientists and experts. "In the Wake of the Sea-Serpents" was his second book; it was translated into English and sold in the United States in 1968. It consisted of his book on sea serpents with parts of his book on the giant squid (and colossal squid) added. As he continued his research, he saw the need to "give a name to the totally new discipline in zoology my research implied. That is how I coined the word 'cryptozoology', the science of hidden animals".