corrected reference

02-attribute-operations.qmd

@@ -61,7 +61,7 @@ Another example is the elevation value (attribute) for a specific grid cell in r
 To illustrate the point, think of a pixel in the 3rd row and the 4th column of a raster matrix.
 Its spatial location is defined by its index in the matrix: move from the origin four cells in the x direction (typically east and right on maps) and three cells in the y direction (typically south and down).
 The raster's resolution defines the distance for each x- and y-step which is specified in a header.
-The header is a vital component of raster datasets which specifies how pixels relate to geographic coordinates (see also Chapter @spatial-operations).
+The header is a vital component of raster datasets which specifies how pixels relate to geographic coordinates (see also @sec-spatial-operations).
 
 This chapter teaches how to manipulate geographic objects based on attributes such as the names of bus stops in a vector dataset and elevations of pixels in a raster dataset. 
 For vector data, this means techniques such as subsetting and aggregation (see @sec-vector-attribute-subsetting and @sec-vector-attribute-aggregation).