de Clercq, S., Talas, S., Soubiran, S., Mägi, R., Nykänen, P. (2008). 
	“Greenwich on the river Tagus”: Reflections on the scientific, cultural and historical significance of Ajuda, the Astronomical Observatory of Lisbon. Opuscula Musealia, 2008, 23-32. doi: https://doi.org/