The phrase "are lacking to date" is correct and usable in written English.
It can be used to indicate that something has not been provided or achieved up until the present time.
Example: "The necessary resources are lacking to date, which has hindered the project's progress."
Alternatives: "are missing so far" or "have not been provided yet."
While a multitude of expressions has been proposed for calculating sample-specific standard errors of prediction when using partial least squares (PLS) regression for the calibration of first-order data, potential generalisations to multiway data are lacking to date.
However, there has never been a study of muroid rodent ultrasound function in the wild and comparisons of USVs produced by wild and laboratory rodents are lacking to date.
Human studies correlating ICP and IAP are lacking to date.
Yet, empirical investigations of this scenario are lacking to date.
One has to consider, however, that Swiss studies addressing issues of speciality choice are lacking to date.
However, despite the development of the DESC is in an advanced stage, population based norms are lacking to date.
However, experimental evidence is lacking to date.
The situation, though, clearly calls for a cogent, creative approach that has been lacking to date.
Kilcullen writes, "Just as the Containment strategy was central to the Cold War, likewise a Disaggregation strategy would provide a unifying strategic conception for the war — something that has been lacking to date".
Although firm experimental evidence for these facts is lacking to date, it is believed that microbial metabolites and effector proteins are released into plant cells for manipulation of the host cytoskeleton, while some secreted plant defensive polypeptides may target the microbial cytoskeleton.
Instead, our work was mainly motivated by [1] and aimed at a global, quantitative analysis that is lacking to date.
