What is the fine-grained topic of the following text: After their arrival Van den Keere's sister married the map maker Jodocus Hondius, a fellow refugee, and it is likely that it was from his brother in law that Van den Keere then learnt cartography and engraving. Only return the topic.
Van den Keere's learning of cartography and engraving from his brother-in-law, Jodocus Hondius.