- 1093/aesa/56.6.792. Hesford,
Clive (January 1998). "The
Parblue Puzzle: Part 4 –
Common Parblue Varieties: The ****atiel [Nymphicus hollandicus]" in The...
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called parblue,
which corresponds to the
colour of the two
preserved Newton's
parakeet specimens. The
reason why only
parblue specimens are known...
- Clive, The
Genetics of
Colour in the
Budgerigar and
other Parrots: The
Parblue Puzzle, Bird Hobbyist,
archived from the
original on 16 May 2006 Bergmann...
- The
Budgerigar Bulletin (39): 74,
September 1936 Hesford, Clive, The
Parblue Puzzle,
archived from the
original on 14 June 2006 Bergman, P, Gene function...
- Cobalts'", The
Budgerigar Bulletin (39): 74, Sep 1936 Hesford, C, The
Parblue Puzzle Bergman, P, Gene
function in
Yellowface Budgerigars Onsman, I, Revised...
