Cannot request works

[KnorrFG]

Hey, I tried using the API. This minimal example:

use crossref::*;

fn main() -> Result<()> {
    let client = Crossref::builder().build()?;
    let works =
        client.works(WorksQuery::new("Itech").field_query(FieldQuery::author("Felix Knorr")))?;
    Ok(())
}

Will produce

felix@ryzen-tr:~/tmp/crossrefexample$ cargo run
   Compiling crossrefexample v0.1.0 (/home/felix/tmp/crossrefexample)
warning: unused variable: `works`
 --> src/main.rs:5:9
  |
5 |     let works =
  |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_works`
  |
  = note: `#[warn(unused_variables)]` on by default

warning: 1 warning emitted

    Finished dev [unoptimized + debuginfo] target(s) in 2.20s
     Running `target/debug/crossrefexample`
Error: Error { ctx: 

expected response item of type work-list but got validation-failure }

This will also happen if I add an email address via the builder