private void addReference(final int sourcePosition,
			final int referencePosition) {
		if (srcAndRefPositions == null) {
			srcAndRefPositions = new int[6];
		}
		if (referenceCount >= srcAndRefPositions.length) {
			int[] a = new int[srcAndRefPositions.length + 6];
			System.arraycopy(srcAndRefPositions, 0, a, 0,
					srcAndRefPositions.length);
			srcAndRefPositions = a;
		}
		srcAndRefPositions[referenceCount++] = sourcePosition;
		srcAndRefPositions[referenceCount++] = referencePosition;
	}