Czekala, N.M.; Callison, L. 1996. Pregnancy diagnosis in the black rhinoceros ( Diceros bicornis) by salivary hormone analysis. Zoo Biology 15 (1): 33-44, figs. 1-4. { copied = true; setTimeout(() => copied = false, 10000); }).catch(err => { console.error('Failed to copy:', err); }); " type="button" :class="copied ? 'bg-secondary border-secondary' : 'border-primary hover:bg-primary'" class="group lg:min-w-64 flex items-center justify-between gap-5 border border-solid px-5 py-2 cursor-pointer transition-colors"> PDF download available