257 
ZUYLEN, L. vAN 
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Orthofoto-fotokaart. 
In Geogr. Tijds. 2 (1968) 466—479. 
Orthophoto-, orthophotomap-, and basemap-revision. 
In ITC-Publication A-41/42, 1968, p.29-48, in Canad. Surv. 22 
(1968) 194-205. 
Experimental orthophotomap of Camp Fortune Skiing Area of 
Gatineau Park. 
In The Cartogr. Journ. 5 (1968) 157. 
Production of photomaps. 
In The Cartogr. Journ. 6 (1969) 92-102, 
In ITC-Publication P-3, 1971, p. 57-80. 
e ^