"Down Syndrome." . . . . . . . . "Down's Syndrome. A clinical and cytogenetical investigation. [A thesis.]"@en . "Down's Syndrome" . "Down's Syndrome. A clinical and cytogenetical investigation. [A thesis.]" . . . . . . . . . . "Down's Syndrome : a clinical and cytogenetical investigation"@en . "Down's Syndrome : a clinical and cytogenetical investigation" . "Down's syndrome a clinical and cytogenetical investigation"@en . . . . . . . . "Down's syndrome; a clinical and cytogenetical investigation" . "Down's syndrome" . . . "Down's syndrome : a clinical and cytogenetical investigation" . "Down's syndrome : a clinical and cytogenetical investigation"@en .