Sentence:  In the last <WSD>few</WSD> years , the application of chromatographic and other modern techniques to the problem of isolating TSH has led to further purification ( Bates and Condliffe , 1960 ; Pierce , Carsten and Wynston , 1960 ) . 
Meaning of the word marked with <WSD> tags:  a quantifier that can be used with count nouns and is often preceded by `a'; a small but indefinite number