■■■■ 
Suède. 
36. B. Hallert : Basic factors limiting the accuracy of mapping and aero- 
triangulation by photo grammetric procedures. Mapping and Charting 
Research Laboratory, Ohio State University, Columbus, Ohio. 5th, 
6th, 7th and 8th interim technical reports 1954 and 1955. 
37. B. Hallert : The use of mirror stereoscope and parallax-bar for the 
treatment of some problems in aerial photogrammetry. Technical, 
paper 192. Ohio State University. M.C.R.L. 
38. B. Hallert : Some remarks concerning the theory of errors for conver 
gent aerial pictures in comparison with near vertical pictures. Phot. 
Eng., 1954, n° 5. 
38a. B. Hallert : Uber die Fehlertheorie der Aerotriangulation und einzelner 
Bildpaare. Zeitschr. f. Verm., 1955, 10, 12. 
39. P.-O. Fagerholm : A study of mechanical radial triangulation and some 
related problems in modern mapping (Dissertation, Stockholm, 1952). 
40. L. Ekelund : Photo grammetric triangulation with separately orientated 
stereo-models. Photogrammetria, 1951/52, 4. 
40a. L. Ekelund : Mekanisk Modelltriangulering Fotogrammetriska Uedde- 
landen. Kungl. Tekniska Hogskolan, Stockholm, 1954. 
Suisse. 
41. M. Zeller : Beispiel einer Lufttriangulation mit Blockausgleichung. 
Schweiz. Zeitschr. fiir Vermessung, Kulturtechnik und Photogr., 
Heft 4, 1953. 
34 
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