Several routes were considered, including variations on previous ideas, but nothing more was done at the time.
These changes can be caused by natural processes on Earth, external factors including variations in sunlight intensity, and more recently by human activities.
Some are very close to Doyle's plot, others including variations.
The book offers hundreds of recipes, including variations.
Colour is variable including pale green, red with yellow tips and other variations.
For further programme times, including repeats and national variations, please see the upcoming episodes page.
The number of official stamps is 782, including variations 902.
The official number of images was 2811, but including variations around 3010 stamps are known.
Others have different features including variations of numbers of dancers and distinctive movements.
One can learn from everything, including possible variations of results ... or their absence.