Variants N.V. Vliegtuigbouw 013 Sagitta

^ taylor, john w.r. frhists. araes (1962). jane s world s aircraft 1962-63. london: sampson, low, marston & co ltd. 
^ cite error: named reference sd invoked never defined (see page).
^ cite error: named reference soaringnov83 invoked never defined (see page).
^ rogers, bennett: 1974 sailplane directory, soaring magazine, page709. soaring society of america, august 1974. usps 499-920