APA
Harmer S. F. (., Shipley A. E. (., . (1923). Cambridge natural history (vol-4): protozea, crustacea, trilebites, introduction to arachinda and king crabs eurypterida, scorpions, spiders, mites, ticks etc. tardigrada (water bears) pentastomida pycnogonida. London: Macmillan.
Chicago
Harmer S F (ed.), Shipley A E (ed.), . 1923. Cambridge natural history (vol-4): protozea, crustacea, trilebites, introduction to arachinda and king crabs eurypterida, scorpions, spiders, mites, ticks etc. tardigrada (water bears) pentastomida pycnogonida. London: Macmillan.
Harvard
Harmer S. F. (., Shipley A. E. (., . (1923). Cambridge natural history (vol-4): protozea, crustacea, trilebites, introduction to arachinda and king crabs eurypterida, scorpions, spiders, mites, ticks etc. tardigrada (water bears) pentastomida pycnogonida. London: Macmillan.
MLA
Harmer S F (ed.), Shipley A E (ed.), . Cambridge natural history (vol-4): protozea, crustacea, trilebites, introduction to arachinda and king crabs eurypterida, scorpions, spiders, mites, ticks etc. tardigrada (water bears) pentastomida pycnogonida. London: Macmillan. 1923.