I was under the impression this is valid SQLite syntax:

SELECT
  *,
  (SELECT amount AS target 
     FROM target_money 
    WHERE start_year <= p.bill_year 
      AND start_month <= p.bill_month 
 ORDER BY start_year ASC, start_month ASC 
    LIMIT 1) AS target
FROM payments AS p;

But I guess it's not, because SQLite returns this error:

no such column: p.bill_year

What's wrong with how I refer to p.bill_year?
Yes, I am positive table payments hosts a column bill_year. Am I crazy or is this just valid SQL syntax? It would work in MySQL wouldn't it?? I don't have any other SQL present so I can't test others, but I thought SQLite was quite standardlike.