Every reference with a DOI in the deposited reference list resolved to a known
work in Crossref or DataCite at the dated check, and none carried a retraction,
withdrawal, or removal notice.
1 without a DOI — not checked. A reference
deposited without a DOI is never matched by title or guessed at; it stays outside the checked
set, and this line discloses that.
Quantitation of blood and plasma amino acids using isotope dilution electron impact gas chromatography/mass spectrometry with U‐13C amino acids as internal standards
Field and laboratory experiments on net uptake of nitrate and ammonium by the roots of spruce (<i>Picea abies</i>) and beech (<i>Fagus sylvatica</i>) trees
Quantitative analysis of amino acids in conifer tissues by high-performance liquid chromatography and fluorescence detection of their 9-fluorenylmethyl chloroformate derivatives
Gas Chromatography-Mass Spectrometry of N- Heptafluorobutyryl Isobutyl Esters of Amino Acids in the Analysis of the Kinetics of [<sup>15</sup>N]H<sub>4</sub><sup>+</sup> Assimilation in <i>Lemna minor</i> L
Soluble N compounds in trees exposed to high loads of N: a comparison of spruce (<i>Picea abies</i>) and beech (<i>Fagus sylvatica</i>) grown under field conditions
Amino acids as a nitrogen source in temperate upland grasslands: the use of dual labelled (13C,15N) glycine to test for direct uptake by dominant grasses
Capillary gas chromatographic determination of proteins and biological amino acids as N(O)-tert.-butyldimethylsilyl derivatives
The 1 reference without a DOI — listed, not checked
no DOI — not checkedAmino acids and derivatives. The biochemistry of plants: A comprehensive treatise
What this badge says. CiteStamped means the CHECKABLE references of this
work were clean at the dated check: each resolved to a known work in a public registry, and none
carried a retraction notice at that time. It says nothing about the quality, findings,
or importance of the work itself, and nothing about references deposited without a DOI.
checked 2026-07-24 — re-checked daily as this page is visited;
titles and statuses come from Crossref and DataCite and are not part of the signed record
Both snippets point at the live badge image and link back to this page. The
badge re-renders from the daily check, so an embed never goes stale by more than a day of visits.